added migration generation

src/main/java/jef/model/DbContext.java

@@ -1,4 +1,6 @@
 package jef.model;
 
 public abstract class DbContext {
+    public void onModelCreate(ModelBuilder mb) {
+    }
 }

src/main/java/jef/model/DbEntity.java

@@ -8,9 +8,12 @@ import jef.model.constraints.ForeignKeyConstraint;
 import jef.model.constraints.IndexConstraint;
 import jef.model.constraints.KeyConstraint;
 import jef.model.constraints.PrimaryKeyConstraint;
-import jef.model.constraints.UniqueConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
 import jef.serializable.SerializableFunction;
 import jef.serializable.SerializableObject;
+import jef.util.Check;
+import jef.util.Util;
+import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.Setter;
 
@@ -18,33 +21,66 @@ import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 @Getter
 @Setter
 public class DbEntity<T extends SerializableObject> {
-    private final Class<T> type;
+    private final String typeName;
+    @Setter(value = AccessLevel.PACKAGE)
+    private Class<T> type;
     private final List<DbField<?>> fields;
     private String name;
     private PrimaryKeyConstraint primaryKey;
     private final List<ForeignKeyConstraint> foreignKeys = new ArrayList<>();
-    private final List<UniqueConstraint> uniqueKeys = new ArrayList<>();
+    private final List<UniqueKeyConstraint> uniqueKeys = new ArrayList<>();
     private final List<KeyConstraint> keys = new ArrayList<>();
     private final List<IndexConstraint> indexes = new ArrayList<>();
 
-    DbEntity(Class<T> type) {
+    //only used for migrations
-        this(type, new ArrayList<>());
+    DbEntity(String typeName) {
+        this.type = (Class) Util.tryGet(() -> Class.forName(typeName)).orElse(null);
+        this.typeName = typeName;
+        this.fields = new ArrayList<>();
+        var split = typeName.split("\\.");
+        this.name = split[split.length - 1];
     }
 
-    DbEntity(Class<T> type, List<DbField<?>> fields) {
+    DbEntity(Class<T> type) {
-        this.type = type;
+        this(type, type.getSimpleName());
-        this.fields = fields;
+    }
-        this.name = type.getSimpleName();
+
+    DbEntity(Class<T> type, String name) {
+        this(type, name, new ArrayList<>());
+    }
+
+    DbEntity(Class<T> type, String name, List<DbField<?>> fields) {
+        this.type = Check.notNull(type, "type");
+        this.typeName = type.getName();
+        this.fields = Check.notNull(fields, "fields");
+        this.name = Check.notNull(name, "name");
     }
 
     public List<DbField<?>> getFields() {
         return Collections.unmodifiableList(fields);
     }
 
+    public List<ForeignKeyConstraint> getForeignKeys() {
+        return Collections.unmodifiableList(foreignKeys);
+    }
+
+    public List<UniqueKeyConstraint> getUniqueKeys() {
+        return Collections.unmodifiableList(uniqueKeys);
+    }
+
+    public List<KeyConstraint> getKeys() {
+        return Collections.unmodifiableList(keys);
+    }
+
+    public List<IndexConstraint> getIndexes() {
+        return Collections.unmodifiableList(indexes);
+    }
+
     /**
      * Returns the database model for the requested property or null if not present.
      *
@@ -62,6 +98,10 @@ public class DbEntity<T extends SerializableObject> {
         return (DbField<R>) fields.stream().filter(e -> e.getField().equals(field)).findFirst().orElse(null);
     }
 
+    public <R> DbField<R> getField(String name) {
+        return (DbField<R>) fields.stream().filter(e -> e.getName().equals(name)).findFirst().orElse(null);
+    }
+
     public <R> DbField<R> getOrCreateField(SerializableFunction<T, R> getter) {
         try {
             var prop = getField(getter);
@@ -93,6 +133,19 @@ public class DbEntity<T extends SerializableObject> {
         }
     }
 
+    public <R> DbField<R> getOrCreateField(String name, String typeName) {
+        try {
+            var prop = (DbField<R>) fields.stream().filter(e -> e.getName().equals(name)).findFirst().orElse(null);
+            if (prop == null) {
+                prop = new DbField<>(this, name, typeName);
+                fields.add(prop);
+            }
+            return prop;
+        } catch (Exception e) {
+            throw new RuntimeException("Invalid expression", e);
+        }
+    }
+
     public <R> DbField<R> addIfAbsent(DbField<R> field) {
         try {
             var prop = (DbField<R>) fields.stream().filter(e -> e.getName().equals(field.getName())).findFirst().orElse(null);
@@ -106,6 +159,26 @@ public class DbEntity<T extends SerializableObject> {
         }
     }
 
+    public boolean dropField(DbField<?> field) {
+        return this.fields.remove(field);
+    }
+
+    public boolean dropForeignKey(ForeignKeyConstraint foreignKey) {
+        return this.foreignKeys.remove(foreignKey);
+    }
+
+    public boolean dropUniqueKey(UniqueKeyConstraint uniqueKey) {
+        return this.uniqueKeys.remove(uniqueKey);
+    }
+
+    public boolean dropKey(KeyConstraint key) {
+        return this.keys.remove(key);
+    }
+
+    public boolean dropIndex(IndexConstraint index) {
+        return this.indexes.remove(index);
+    }
+
     private <R> String extractFieldName(SerializableFunction<T, R> getter) {
         try {
             var expr = new AsmParser(getter).parse();
@@ -125,15 +198,9 @@ public class DbEntity<T extends SerializableObject> {
         }
     }
 
-    public void addUniqueContstraint(UniqueConstraint uniqueConstraint) {
+    public void addUniqueKey(UniqueKeyConstraint uniqueKeyConstraint) {
-        if (!uniqueKeys.contains(uniqueConstraint)) {
+        if (!uniqueKeys.contains(uniqueKeyConstraint)) {
-            uniqueKeys.add(uniqueConstraint);
+            uniqueKeys.add(uniqueKeyConstraint);
-        }
-    }
-
-    public void addIndex(IndexConstraint index) {
-        if (!indexes.contains(index)) {
-            indexes.add(index);
         }
     }
 
@@ -143,11 +210,37 @@ public class DbEntity<T extends SerializableObject> {
         }
     }
 
+    public void addIndex(IndexConstraint index) {
+        if (!indexes.contains(index)) {
+            indexes.add(index);
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DbEntity<?> dbEntity = (DbEntity<?>) o;
+        return typeName.equals(dbEntity.typeName)
+               && fields.equals(dbEntity.fields)
+               && name.equals(dbEntity.name)
+               && Objects.equals(primaryKey, dbEntity.primaryKey)
+               && foreignKeys.equals(dbEntity.foreignKeys)
+               && uniqueKeys.equals(dbEntity.uniqueKeys)
+               && keys.equals(dbEntity.keys)
+               && indexes.equals(dbEntity.indexes);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(typeName, type, fields, name, primaryKey, foreignKeys, uniqueKeys, keys, indexes);
+    }
+
     @Override
     public String toString() {
         return "DbEntity{" +
-                "type=" + type +
+               "type=" + type +
-                ", name='" + name + '\'' +
+               ", name='" + name + '\'' +
-                '}';
+               '}';
     }
 }

src/main/java/jef/model/DbField.java

@@ -2,8 +2,10 @@ package jef.model;
 
 import jef.model.constraints.IndexConstraint;
 import jef.model.constraints.KeyConstraint;
-import jef.model.constraints.UniqueConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
 import jef.serializable.SerializableObject;
+import jef.util.Check;
+import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.Setter;
 
@@ -11,28 +13,43 @@ import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 
 @Getter
 @Setter
 public class DbField<T> {
     private final DbEntity<? extends SerializableObject> entity;
-    private final Class<T> type;
+    private final String typeName;
-    private final Field field;
+    @Setter(value = AccessLevel.PACKAGE)
+    private Class<T> type;
+    @Setter(value = AccessLevel.PACKAGE)
+    private Field field;
     private boolean isModelField;
     private boolean isDatabaseField;
     private DbField<?> foreignKeyModelLink;
     private String name;
     private boolean notNull = false;
 
+    DbField(DbEntity<? extends SerializableObject> entity, String name, String typeName) {
+        this.entity = Check.notNull(entity, "entity");
+        this.type = null;
+        this.typeName = Check.notNull(typeName, "typeName");
+        this.field = null;
+        this.name = Check.notNull(name, "name");
+        this.isModelField = false;
+        this.isDatabaseField = true;
+    }
+
     DbField(DbEntity<? extends SerializableObject> entity, Class<T> type, Field field) {
         this(entity, type, field, field.getName());
     }
 
     DbField(DbEntity<? extends SerializableObject> entity, Class<T> type, Field field, String name) {
-        this.entity = entity;
+        this.entity = Check.notNull(entity, "entity");
-        this.type = type;
+        this.type = Check.notNull(type, "type");
+        this.typeName = type.getName();
         this.field = field;
-        this.name = name;
+        this.name = Check.notNull(name, "name");
         this.isModelField = field != null;
         this.isDatabaseField = !Collection.class.isAssignableFrom(type) && !SerializableObject.class.isAssignableFrom(type);
     }
@@ -48,9 +65,9 @@ public class DbField<T> {
     public void setUnique(boolean unique) {
         var constr = entity.getUniqueKeys().stream().filter(u -> u.getFields().size() == 1 && u.getFields().get(0) == this).findFirst();
         if (!constr.isPresent() && unique) {
-            entity.getUniqueKeys().add(new UniqueConstraint(entity, new ArrayList<>(List.of(this))));
+            entity.addUniqueKey(new UniqueKeyConstraint(entity, new ArrayList<>(List.of(this))));
         } else if (constr.isPresent() && !unique) {
-            entity.getUniqueKeys().remove(constr.get());
+            entity.dropUniqueKey(constr.get());
         } //else do nothing
     }
 
@@ -61,9 +78,9 @@ public class DbField<T> {
     public void setIndex(boolean indexed) {
         var constr = entity.getIndexes().stream().filter(u -> u.getFields().size() == 1 && u.getFields().get(0) == this).findFirst();
         if (!constr.isPresent() && indexed) {
-            entity.getIndexes().add(new IndexConstraint(entity, new ArrayList<>(List.of(this))));
+            entity.addIndex(new IndexConstraint(entity, new ArrayList<>(List.of(this))));
         } else if (constr.isPresent() && !indexed) {
-            entity.getIndexes().remove(constr.get());
+            entity.dropIndex(constr.get());
         } //else do nothing
     }
 
@@ -74,18 +91,68 @@ public class DbField<T> {
     public void setKey(boolean keyed) {
         var constr = entity.getKeys().stream().filter(u -> u.getFields().size() == 1 && u.getFields().get(0) == this).findFirst();
         if (!constr.isPresent() && keyed) {
-            entity.getKeys().add(new KeyConstraint(entity, new ArrayList<>(List.of(this))));
+            entity.addKey(new KeyConstraint(entity, new ArrayList<>(List.of(this))));
         } else if (constr.isPresent() && !keyed) {
-            entity.getKeys().remove(constr.get());
+            entity.dropKey(constr.get());
         } //else do nothing
     }
 
+    public DbField<T> setModelField(boolean modelField) {
+        isModelField = modelField;
+        return this;
+    }
+
+    public DbField<T> setDatabaseField(boolean databaseField) {
+        isDatabaseField = databaseField;
+        return this;
+    }
+
+    public DbField<T> setNotNull(boolean notNull) {
+        this.notNull = notNull;
+        return this;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!equalsCommon(o)) {
+            return false;
+        }
+        DbField<?> dbField = (DbField<?>) o;
+        return name.equals(dbField.name);
+//               && Objects.equals(field == null ? null : field.getName(), dbField.field == null ? null : dbField.field.getName());
+    }
+
+    public boolean equalsExceptName(Object o) {
+        return equalsCommon(o);
+    }
+
+    private boolean equalsCommon(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DbField<?> dbField = (DbField<?>) o;
+        return isModelField == dbField.isModelField
+               && isDatabaseField == dbField.isDatabaseField
+               && notNull == dbField.notNull
+               && entity.getName().equals(dbField.entity.getName())
+               && typeName.equals(dbField.typeName)
+//               && Objects.equals(type, dbField.type)
+               && Objects.equals(foreignKeyModelLink == null ? null : foreignKeyModelLink.getName(),
+                                 dbField.foreignKeyModelLink == null ? null : dbField.foreignKeyModelLink.getName());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(entity.getName(), typeName, type, field == null ? null : field.getName(), isModelField, isDatabaseField,
+                            foreignKeyModelLink == null ? null : foreignKeyModelLink.getName(),
+                            name, notNull);
+    }
+
     @Override
     public String toString() {
         return "DbField{" +
-                "name=" + name +
+               "name=" + name +
-                ", type=" + type.getSimpleName() + (notNull ? "" : "?") +
+               ", typeName=" + typeName + (notNull ? "" : "?") +
-                ", entity=" + entity +
+               ", entity=" + entity +
-                '}';
+               '}';
     }
 }

src/main/java/jef/model/EntityInitializer.java

@@ -19,12 +19,13 @@ class EntityInitializer {
                 throw new ModelException("DbSet " + ctxfield.getName() + " is missing the " + Clazz.class.getSimpleName() + " annotation");
             }
             var dbsetClazz = (Class<? extends SerializableObject>) clazzAnnotation.clazz();
-            initEntity(mb, dbsetClazz);
+            initEntity(mb, dbsetClazz, ctxfield.getName());
         }
     }
 
-    static void initEntity(ModelBuilder mb, Class<? extends SerializableObject> clazz) {
+    static void initEntity(ModelBuilder mb, Class<? extends SerializableObject> clazz, String name) {
         var entity = mb.getOrCreateEntity(clazz);
+        entity.setName(name);
 
         var fields = ReflectionUtil.getFieldsRecursive(clazz);
         for (var f : fields) {

src/main/java/jef/model/ForeignKeyInitializer.java

@@ -33,7 +33,7 @@ class ForeignKeyInitializer {
                 }
                 var otherEntity = mb.getEntity((Class<? extends SerializableObject>) clazzAnnotation.clazz());
                 if (otherEntity == null) {
-                    EntityInitializer.initEntity(mb, (Class<? extends SerializableObject>) clazzAnnotation.clazz());
+                    EntityInitializer.initEntity(mb, (Class<? extends SerializableObject>) clazzAnnotation.clazz(), f.getName());
                     otherEntity = mb.getEntity((Class<? extends SerializableObject>) clazzAnnotation.clazz());
                     PrimaryKeyInitializer.initPrimaryKeys(mb, otherEntity);
                 }
@@ -88,7 +88,7 @@ class ForeignKeyInitializer {
             } else if (SerializableObject.class.isAssignableFrom(f.getType())) {
                 var otherEntity = mb.getEntity((Class<? extends SerializableObject>) f.getType());
                 if (otherEntity == null) {
-                    EntityInitializer.initEntity(mb, (Class<? extends SerializableObject>) f.getType());
+                    EntityInitializer.initEntity(mb, (Class<? extends SerializableObject>) f.getType(), f.getName());
                     otherEntity = mb.getEntity((Class<? extends SerializableObject>) f.getType());
                     PrimaryKeyInitializer.initPrimaryKeys(mb, otherEntity);
                 }

src/main/java/jef/model/ModelBuilder.java

@@ -6,16 +6,23 @@ import jef.model.annotations.processors.IndexProcessor;
 import jef.model.annotations.processors.KeyProcessor;
 import jef.model.annotations.processors.NotNullProcessor;
 import jef.model.annotations.processors.UniqueProcessor;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.constraints.IndexConstraint;
+import jef.model.constraints.KeyConstraint;
+import jef.model.constraints.PrimaryKeyConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
 import jef.serializable.SerializableObject;
+import jef.util.Check;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 public class ModelBuilder {
     private static final List<AnnotationProcessor> annotationProcessors = new ArrayList<>();
 
-    static {
+    static {//TODO move this to a passable config class
         annotationProcessors.add(NotNullProcessor.INSTANCE);
         annotationProcessors.add(UniqueProcessor.INSTANCE);
         annotationProcessors.add(IndexProcessor.INSTANCE);
@@ -23,7 +30,13 @@ public class ModelBuilder {
         annotationProcessors.add(ForeignKeyProcessor.INSTANCE);
     }
 
-    public static ModelBuilder from(Class<? extends DbContext> context) {
+    /**
+     * Initializes a ModelBuilder and configures the entities found in the context Class according to annotations.
+     *
+     * @param context the context to use for initialization
+     * @return an initialized ModelBuilder
+     */
+    public static ModelBuilder from(Class<? extends DbContext> context) { //TODO pass optional config here
         try {
             return from0(context);
         } catch (Exception e) {
@@ -40,15 +53,34 @@ public class ModelBuilder {
         for (AnnotationProcessor processor : annotationProcessors) {
             processor.apply(mb);
         }
+
+        var instance = context.getDeclaredConstructor().newInstance();//TODO find constructor, //TODO optionally with config
+        instance.onModelCreate(mb);
+
         return mb;
     }
 
     private final List<DbEntity<? extends SerializableObject>> entities;
 
-    public ModelBuilder(List<DbEntity<? extends SerializableObject>> entities) {
+    /**
-        this.entities = entities;
+     * Initializes an empty ModelBuilder
+     */
+    public ModelBuilder() {
+        this(List.of());
     }
 
+    /**
+     * Initializes a new ModelBuilder with the provided entities.
+     */
+    public ModelBuilder(List<DbEntity<? extends SerializableObject>> entities) {
+        this.entities = new ArrayList<>(entities);
+    }
+
+    /**
+     * Returns an unmodifiable List of all entities.
+     *
+     * @return an unmodifiable List of all entities
+     */
     public List<DbEntity<? extends SerializableObject>> getEntities() {
         return Collections.unmodifiableList(entities);
     }
@@ -61,22 +93,157 @@ public class ModelBuilder {
      * @return the database model for the requested class or null if not present.
      */
     public <T extends SerializableObject> DbEntity<T> getEntity(Class<T> clazz) {
-        return (DbEntity<T>) entities.stream().filter(e -> e.getType() == clazz).findFirst().orElse(null);
+        Check.notNull(clazz, "clazz");
+        return getEntity(clazz.getName());
     }
 
     /**
-     * Returns the database model for the requested class or creates a new one if none exists.
+     * Returns the database model for the requested type name or null if not present.
+     *
+     * @param typeName the class name (including the package name) of the model class
+     * @param <T>      the type of model class
+     * @return the database model for the requested class or null if not present.
+     */
+    public <T extends SerializableObject> DbEntity<T> getEntity(String typeName) {
+        Check.notNull(typeName, "typeName");
+        return (DbEntity<T>) entities.stream().filter(e -> e.getTypeName().equals(typeName)).findFirst().orElse(null);
+    }
+
+    /**
+     * Returns the DbEntity for the requested class or creates a new empty DbEntity if none exists.
      *
      * @param clazz the class of the model class
      * @param <T>   the type of model class
-     * @return the database model for the requested class or the newly created one if none existed.
+     * @return the DbEntity for the requested class or the newly created empty DbEntity if none existed.
      */
     public <T extends SerializableObject> DbEntity<T> getOrCreateEntity(Class<T> clazz) {
-        var entity = getEntity(clazz);
+        Check.notNull(clazz, "clazz");
+        return getOrCreateEntity(clazz.getName());
+    }
+
+    /**
+     * Returns the DbEntity for the requested class or creates a new empty DbEntity if none exists.
+     *
+     * @param typeName the class name (including package name) of the model class
+     * @param <T>      the type of model class
+     * @return the DbEntity for the requested class or the newly created empty DbEntity if none existed.
+     */
+    public <T extends SerializableObject> DbEntity<T> getOrCreateEntity(String typeName) {
+        Check.notNull(typeName, "typeName");
+        var entity = (DbEntity<T>) getEntity(typeName);
         if (entity == null) {
-            entity = new DbEntity<>(clazz);
+            entity = new DbEntity<>(typeName);
             entities.add(entity);
         }
         return entity;
     }
+
+    /**
+     * Drops the entity from this ModelBuilder. This function also drops referencing foreign keys.
+     *
+     * @param entity the entity to drop
+     * @param <T>    the type of the entity
+     * @return whether the entity was present in this ModelBuilder
+     */
+    public <T extends SerializableObject> boolean dropEntity(DbEntity<T> entity) {
+        Check.notNull(entity, "entity");
+        var removed = this.entities.remove(entity);
+        if (!removed) {
+            return false;
+        }
+        for (DbEntity<? extends SerializableObject> e : this.entities) {
+            e.getForeignKeys().stream()
+                    .filter(fk -> fk.getReferencedEntity() == entity)
+                    .toList()
+                    .forEach(e::dropForeignKey);
+        }
+        return removed;
+    }
+
+    public ModelBuilder clone() {
+        //copy entities
+        var entities = new ArrayList<DbEntity>();
+        for (int i = 0; i < this.entities.size(); i++) {
+            var old = this.entities.get(i);
+            var entity = (DbEntity<?>) new DbEntity(old.getTypeName());
+            entity.setName(old.getName());
+            entity.setType((Class) old.getType());
+
+            //add fields
+            old.getFields().stream().map(e -> {
+                        var nf = new DbField(entity, e.getName(), e.getTypeName());
+                        nf.setField(e.getField());
+                        nf.setType(e.getType());
+                        nf.setNotNull(e.isNotNull());
+                        nf.setModelField(e.isModelField());
+                        nf.setDatabaseField(e.isDatabaseField());
+                        return nf;
+                    })
+                    .forEach(entity::addIfAbsent);
+
+            //apply exposed foreign keys
+            old.getFields().stream().filter(e -> e.getForeignKeyModelLink() != null).forEach(e -> {
+                var nf = entity.getFields().stream().filter(f -> f.getName().equals(e.getName())).findFirst().get(); //get(): should always be there
+                nf.setForeignKeyModelLink(old.getFields().stream().filter(f -> f.getName().equals(e.getForeignKeyModelLink().getName())).findFirst().get()); //get(): should always be there
+            });
+
+            entity.setName(old.getName());
+            if (old.getPrimaryKey() != null) {
+                var newPkFields = old.getPrimaryKey().getFields().stream()
+                        .map(pkfield -> entity.getFields().stream().filter(f -> f.getName().equals(pkfield.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                entity.setPrimaryKey(new PrimaryKeyConstraint(entity, (List) newPkFields));
+            }
+            entities.add(entity);
+        }
+
+        //copy keys
+        for (int i = 0; i < entities.size(); i++) {
+            var entity = entities.get(i);
+            var old = this.entities.get(i);
+            for (ForeignKeyConstraint foreignKey : old.getForeignKeys()) {
+                var fkFields = foreignKey.getFields().stream()
+                        .map(fkField -> entity.getFields().stream().filter(f -> ((DbField) f).getName().equals(fkField.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                var refEntity = entities.stream().filter(e -> e.getName().equals(foreignKey.getReferencedEntity().getName())).findFirst().get();//should always be there
+                var fkRefFields = foreignKey.getReferencedFields().stream()
+                        .map(fkField -> refEntity.getFields().stream().filter(f -> ((DbField) f).getName().equals(fkField.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                entities.get(i).addForeignKey(new ForeignKeyConstraint(entity, (List) fkFields, refEntity, (List) fkRefFields, foreignKey.getOnUpdate(), foreignKey.getOnDelete()));
+            }
+
+            for (UniqueKeyConstraint uniqueKey : old.getUniqueKeys()) {
+                var newUkFields = uniqueKey.getFields().stream()
+                        .map(ukField -> entity.getFields().stream().filter(f -> ((DbField) f).getName().equals(ukField.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                entity.addUniqueKey(new UniqueKeyConstraint(entity, (List) newUkFields));
+            }
+            for (KeyConstraint key : old.getKeys()) {
+                var newKFields = key.getFields().stream()
+                        .map(kField -> entity.getFields().stream().filter(f -> ((DbField) f).getName().equals(kField.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                entity.addKey(new KeyConstraint(entity, (List) newKFields));
+            }
+            for (IndexConstraint index : old.getIndexes()) {
+                var newIFields = index.getFields().stream()
+                        .map(iField -> entity.getFields().stream().filter(f -> ((DbField) f).getName().equals(iField.getName())).findFirst().get()) //get(): should always be there
+                        .toList();
+                entity.addIndex(new IndexConstraint(entity, (List) newIFields));
+            }
+        }
+        return new ModelBuilder((List) entities);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ModelBuilder that = (ModelBuilder) o;
+        return entities.equals(that.entities);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(entities);
+    }
 }

src/main/java/jef/model/annotations/processors/UniqueProcessor.java

@@ -3,13 +3,13 @@ package jef.model.annotations.processors;
 import jef.model.DbEntity;
 import jef.model.DbField;
 import jef.model.annotations.Unique;
-import jef.model.constraints.UniqueConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
 import jef.serializable.SerializableObject;
 
 import java.lang.annotation.Annotation;
 import java.util.List;
 
-public class UniqueProcessor extends KeyProcessorBase<UniqueConstraint, Unique> {
+public class UniqueProcessor extends KeyProcessorBase<UniqueKeyConstraint, Unique> {
     public static final UniqueProcessor INSTANCE = new UniqueProcessor();
 
     private UniqueProcessor() {
@@ -17,13 +17,13 @@ public class UniqueProcessor extends KeyProcessorBase<UniqueConstraint, Unique>
     }
 
     @Override
-    protected UniqueConstraint initConstraint(DbEntity<? extends SerializableObject> entity, List<DbField<?>> fields) {
+    protected UniqueKeyConstraint initConstraint(DbEntity<? extends SerializableObject> entity, List<DbField<?>> fields) {
-        return new UniqueConstraint(entity, fields);
+        return new UniqueKeyConstraint(entity, fields);
     }
 
     @Override
-    protected void addConstraint(UniqueConstraint constr) {
+    protected void addConstraint(UniqueKeyConstraint constr) {
-        constr.getEntity().addUniqueContstraint(constr);
+        constr.getEntity().addUniqueKey(constr);
     }
 
     @Override

src/main/java/jef/model/constraints/ConstraintBase.java

@@ -0,0 +1,37 @@
+package jef.model.constraints;
+
+import jef.model.DbEntity;
+import jef.model.DbField;
+import jef.util.Check;
+import lombok.Getter;
+
+import java.util.List;
+import java.util.Objects;
+
+@Getter
+public abstract class ConstraintBase implements Constraint {
+    protected final DbEntity<?> entity;
+    protected final List<DbField<?>> fields;
+
+    public ConstraintBase(DbEntity<?> entity, List<DbField<?>> fields) {
+        this.entity = Check.notNull(entity, "entity");
+        this.fields = Check.notNull(fields, "fields");
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ConstraintBase that = (ConstraintBase) o;
+
+        //only compare names
+        return entity.getName().equals(that.entity.getName())
+               && fields.stream().map(DbField::getName).toList().equals(that.fields.stream().map(DbField::getName).toList());
+    }
+
+    @Override
+    public int hashCode() {
+        //only hash names
+        return Objects.hash(entity.getName(), fields.stream().map(DbField::getName).toList());
+    }
+}

src/main/java/jef/model/constraints/ForeignKeyConstraint.java

@@ -2,24 +2,47 @@ package jef.model.constraints;
 
 import jef.model.DbEntity;
 import jef.model.DbField;
-import lombok.AllArgsConstructor;
-import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 @Getter
-@AllArgsConstructor
+public class ForeignKeyConstraint extends ConstraintBase {
-@EqualsAndHashCode
-public class ForeignKeyConstraint implements Constraint {
-    private final DbEntity<?> entity;
-    private final List<DbField<?>> fields;
     private final DbEntity<?> referencedEntity;
     private final List<DbField<?>> referencedFields;
     private final Action onUpdate;
     private final Action onDelete;
 
+    public ForeignKeyConstraint(DbEntity<?> entity, List<DbField<?>> fields, DbEntity<?> referencedEntity, List<DbField<?>> referencedFields, Action onUpdate, Action onDelete) {
+        super(entity, fields);
+        this.referencedEntity = referencedEntity;
+        this.referencedFields = referencedFields;
+        this.onUpdate = onUpdate;
+        this.onDelete = onDelete;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        ForeignKeyConstraint that = (ForeignKeyConstraint) o;
+
+//only compare names
+        return referencedEntity.getName().equals(that.referencedEntity.getName())
+               && referencedFields.stream().map(DbField::getName).toList().equals(that.referencedFields.stream().map(DbField::getName).toList())
+               && onUpdate == that.onUpdate
+               && onDelete == that.onDelete;
+    }
+
+    @Override
+    public int hashCode() {
+        //only hash names
+        return Objects.hash(super.hashCode(), referencedEntity.getName(), referencedFields.stream().map(DbField::getName).toList(), onUpdate, onDelete);
+    }
+
     @Override
     public String getName() {
         return "FK_" + entity.getName() + "_" + referencedEntity.getName() + "_" + fields.stream().map(DbField::getName).collect(Collectors.joining("_"));
@@ -28,7 +51,7 @@ public class ForeignKeyConstraint implements Constraint {
     @Override
     public String toString() {
         return "CONSTRAINT " + getName() + " FOREIGN KEY (" + fields.stream().map(DbField::getName).collect(Collectors.joining(", ")) + ") "
-                + "REFERENCES " + referencedEntity.getName() + "(" + referencedFields.stream().map(DbField::getName).collect(Collectors.joining(", ")) + ")";
+               + "REFERENCES " + referencedEntity.getName() + "(" + referencedFields.stream().map(DbField::getName).collect(Collectors.joining(", ")) + ")";
     }
 
     public enum Action {
@@ -36,5 +59,6 @@ public class ForeignKeyConstraint implements Constraint {
         RESTRICT,
         SET_NULL,
         NO_ACTION,
+        ;
     }
 }

src/main/java/jef/model/constraints/IndexConstraint.java

@@ -2,7 +2,6 @@ package jef.model.constraints;
 
 import jef.model.DbEntity;
 import jef.model.DbField;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
@@ -10,11 +9,11 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 @Getter
-@AllArgsConstructor
+@EqualsAndHashCode(callSuper = true)
-@EqualsAndHashCode
+public class IndexConstraint extends ConstraintBase {
-public class IndexConstraint implements Constraint {
+    public IndexConstraint(DbEntity<?> entity, List<DbField<?>> fields) {
-    private final DbEntity<?> entity;
+        super(entity, fields);
-    private final List<DbField<?>> fields;
+    }
 
     @Override
     public String getName() {

src/main/java/jef/model/constraints/KeyConstraint.java

@@ -2,7 +2,6 @@ package jef.model.constraints;
 
 import jef.model.DbEntity;
 import jef.model.DbField;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
@@ -10,11 +9,11 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 @Getter
-@AllArgsConstructor
+@EqualsAndHashCode(callSuper = true)
-@EqualsAndHashCode
+public class KeyConstraint extends ConstraintBase {
-public class KeyConstraint implements Constraint {
+    public KeyConstraint(DbEntity<?> entity, List<DbField<?>> fields) {
-    private final DbEntity<?> entity;
+        super(entity, fields);
-    private final List<DbField<?>> fields;
+    }
 
     @Override
     public String getName() {

src/main/java/jef/model/constraints/PrimaryKeyConstraint.java

@@ -2,7 +2,6 @@ package jef.model.constraints;
 
 import jef.model.DbEntity;
 import jef.model.DbField;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
@@ -10,11 +9,11 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 @Getter
-@AllArgsConstructor
+@EqualsAndHashCode(callSuper = true)
-@EqualsAndHashCode
+public class PrimaryKeyConstraint extends ConstraintBase {
-public class PrimaryKeyConstraint implements Constraint {
+    public PrimaryKeyConstraint(DbEntity<?> entity, List<DbField<?>> fields) {
-    private final DbEntity<?> entity;
+        super(entity, fields);
-    private final List<DbField<?>> fields;
+    }
 
     @Override
     public String getName() {

src/main/java/jef/model/constraints/UniqueKeyConstraint.java

@@ -2,7 +2,6 @@ package jef.model.constraints;
 
 import jef.model.DbEntity;
 import jef.model.DbField;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
@@ -10,11 +9,11 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 @Getter
-@AllArgsConstructor
+@EqualsAndHashCode(callSuper = true)
-@EqualsAndHashCode
+public class UniqueKeyConstraint extends ConstraintBase {
-public class UniqueConstraint implements Constraint {
+    public UniqueKeyConstraint(DbEntity<?> entity, List<DbField<?>> fields) {
-    private final DbEntity<?> entity;
+        super(entity, fields);
-    private final List<DbField<?>> fields;
+    }
 
     @Override
     public String getName() {

src/main/java/jef/model/migration/Migration.java

@@ -0,0 +1,7 @@
+package jef.model.migration;
+
+public interface Migration {
+    void up(MigrationBuilder migrationBuilder);
+
+    void down(MigrationBuilder migrationBuilder);
+}

src/main/java/jef/model/migration/MigrationBuilder.java

@@ -0,0 +1,102 @@
+package jef.model.migration;
+
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.migration.operation.AddFieldOperation;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddIndexOperation;
+import jef.model.migration.operation.AddKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddTableOperation;
+import jef.model.migration.operation.AddUniqueKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropFieldOperation;
+import jef.model.migration.operation.DropTableOperation;
+import jef.model.migration.operation.MigrationOperation;
+import jef.model.migration.operation.RenameFieldOperation;
+import jef.model.migration.operation.RenameTableOperation;
+import jef.model.migration.operation.UpdateFieldOperation;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MigrationBuilder {
+    private final List<MigrationOperation.Builder<?>> operations = new ArrayList<>();
+
+    public AddTableOperation.Builder addTable(String table, List<AddFieldOperation.Builder> fields) {
+        var op = new AddTableOperation.Builder(table, fields);
+        operations.add(op);
+        return op;
+    }
+
+    public RenameTableOperation.Builder renameTable(String oldName, String newName) {
+        var op = new RenameTableOperation.Builder(oldName, newName);
+        operations.add(op);
+        return op;
+    }
+
+    public DropTableOperation.Builder dropTable(String table) {
+        var op = new DropTableOperation.Builder(table);
+        operations.add(op);
+        return op;
+    }
+
+    public AddFieldOperation.Builder addField(String table, String field) {
+        var op = new AddFieldOperation.Builder(table, field);
+        operations.add(op);
+        return op;
+    }
+
+    public RenameFieldOperation.Builder renameField(String table, String oldName, String newName) {
+        var op = new RenameFieldOperation.Builder(table, oldName, newName);
+        operations.add(op);
+        return op;
+    }
+
+    public UpdateFieldOperation.Builder updateField(String table, String field) {
+        var op = new UpdateFieldOperation.Builder(table, field);
+        operations.add(op);
+        return op;
+    }
+
+    public DropFieldOperation.Builder dropField(String table, String field) {
+        var op = new DropFieldOperation.Builder(table, field);
+        operations.add(op);
+        return op;
+    }
+
+    public AddPrimaryKeyOperation.Builder addPrimaryKey(String name, String table, List<String> fields) {
+        var op = new AddPrimaryKeyOperation.Builder(name, table, fields);
+        operations.add(op);
+        return op;
+    }
+
+    public AddForeignKeyOperation.Builder addForeignKey(String name, String table, List<String> fields, String referencedTable, List<String> referencedFields, ForeignKeyConstraint.Action onUpdate, ForeignKeyConstraint.Action onDelete) {
+        var op = new AddForeignKeyOperation.Builder(name, table, fields, referencedTable, referencedFields, onUpdate, onDelete);
+        operations.add(op);
+        return op;
+    }
+
+    public AddUniqueKeyOperation.Builder addUniqueKey(String name, String table, List<String> fields) {
+        var op = new AddUniqueKeyOperation.Builder(name, table, fields);
+        operations.add(op);
+        return op;
+    }
+
+    public AddKeyOperation.Builder addKey(String name, String table, List<String> fields) {
+        var op = new AddKeyOperation.Builder(name, table, fields);
+        operations.add(op);
+        return op;
+    }
+
+    public AddIndexOperation.Builder addIndex(String name, String table, List<String> fields) {
+        var op = new AddIndexOperation.Builder(name, table, fields);
+        operations.add(op);
+        return op;
+    }
+
+    public DropConstraintOperation.Builder dropConstraint(String name, String table) {
+        var op = new DropConstraintOperation.Builder(name, table);
+        operations.add(op);
+        return op;
+    }
+}

src/main/java/jef/model/migration/creator/MigrationBuilderGenerator.java

@@ -0,0 +1,195 @@
+package jef.model.migration.creator;
+
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.migration.Migration;
+import jef.model.migration.MigrationBuilder;
+import jef.model.migration.operation.AddFieldOperation;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddIndexOperation;
+import jef.model.migration.operation.AddKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddTableOperation;
+import jef.model.migration.operation.AddUniqueKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropFieldOperation;
+import jef.model.migration.operation.DropTableOperation;
+import jef.model.migration.operation.MigrationOperation;
+import jef.model.migration.operation.RenameFieldOperation;
+import jef.model.migration.operation.RenameTableOperation;
+import jef.model.migration.operation.UpdateFieldOperation;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+public class MigrationBuilderGenerator {
+    private final List<MigrationOperation> opsUp;
+    private final List<MigrationOperation> opsDown;
+    private final String name;
+    private final String packageName;
+
+    private final Set<Class<?>> imports = new HashSet<>();
+    @Getter
+    private String java = null;
+
+    public MigrationBuilderGenerator generate() {
+        if (java == null) {
+            java = generateMigrationBuilderJava();
+        }
+        return this;
+    }
+
+    private String generateMigrationBuilderJava() {
+        imports.add(Migration.class);
+        imports.add(MigrationBuilder.class);
+
+        //generate java for migration step and concat
+        var migrationUp = String.join("\n\n", opsUp.stream().map(this::getMigrationJava).toList());
+        var migrationDown = String.join("\n\n", opsDown.stream().map(this::getMigrationJava).toList());
+
+        //generate migration class file
+        var normalImports = imports.stream().filter(e -> !e.getName().startsWith("java")).sorted(Comparator.comparing(Class::getName, String.CASE_INSENSITIVE_ORDER)).toList();
+        var javaImports = imports.stream().filter(e -> e.getName().startsWith("java")).sorted(Comparator.comparing(Class::getName, String.CASE_INSENSITIVE_ORDER)).toList();
+        var java = "package " + packageName + ";\n"
+                        + "\n"
+                        + normalImports.stream().map(e -> "import " + e.getName().replace("$", ".") + ";").collect(Collectors.joining("\n")) + "\n\n"
+                        + javaImports.stream().map(e -> "import " + e.getName().replace("$", ".") + ";").collect(Collectors.joining("\n")) + "\n\n"
+                        + "public class " + name + " implements Migration {\n"
+                        + "    public void up(MigrationBuilder mb) {\n"
+                        + "        " + migrationUp.replace("\n", "\n        ") + "\n"
+                        + "    }\n"
+                        + "\n"
+                        + "    public void down(MigrationBuilder mb) {\n"
+                        + "        " + migrationDown.replace("\n", "\n        ") + "\n"
+                        + "    }\n"
+                        + "}\n";
+        return java;
+    }
+
+    //mapper stuff
+    private final Map<Class<? extends MigrationOperation>, Function<? extends MigrationOperation, String>> OP_TO_STRING_MAPPERS = initMapper();
+    private final Function<MigrationOperation, String> UNSUPPORTED_MIGRATION_OPERATION_FUNCTION = (MigrationOperation i) -> {
+        throw new RuntimeException(new UnsupportedOperationException("Unsupported migration operation: " + i.getClass().getSimpleName()));
+    };
+
+    private Map<Class<? extends MigrationOperation>, Function<? extends MigrationOperation, String>> initMapper() {
+        Map<Class<? extends MigrationOperation>, Function<? extends MigrationOperation, String>> map = new HashMap<>();
+        map.put(AddFieldOperation.class, (AddFieldOperation op) -> addFieldOp(op));
+        map.put(AddForeignKeyOperation.class, (AddForeignKeyOperation op) -> addForeignKeyOp(op));
+        map.put(AddIndexOperation.class, (AddIndexOperation op) -> addIndexOp(op));
+        map.put(AddKeyOperation.class, (AddKeyOperation op) -> addKeyOp(op));
+        map.put(AddPrimaryKeyOperation.class, (AddPrimaryKeyOperation op) -> addPrimaryKeyOp(op));
+        map.put(AddTableOperation.class, (AddTableOperation op) -> addTableOp(op));
+        map.put(AddUniqueKeyOperation.class, (AddUniqueKeyOperation op) -> addUniqueKeyOp(op));
+        map.put(DropConstraintOperation.class, (DropConstraintOperation op) -> dropConstraintOp(op));
+        map.put(DropFieldOperation.class, (DropFieldOperation op) -> dropFieldOp(op));
+        map.put(DropTableOperation.class, (DropTableOperation op) -> dropTableOp(op));
+        map.put(RenameFieldOperation.class, (RenameFieldOperation op) -> renameFieldOp(op));
+        map.put(RenameTableOperation.class, (RenameTableOperation op) -> renameTableOp(op));
+        map.put(UpdateFieldOperation.class, (UpdateFieldOperation op) -> updateField(op));
+        return map;
+    }
+
+    private String getMigrationJava(MigrationOperation migrationOperation) {
+        var mapper = ((Function<MigrationOperation, String>)
+                OP_TO_STRING_MAPPERS.getOrDefault(migrationOperation.getClass(), UNSUPPORTED_MIGRATION_OPERATION_FUNCTION));
+        return mapper.apply(migrationOperation);
+    }
+
+    private String addFieldOp(AddFieldOperation op) {
+        return "mb.addField(\"" + op.getTable() + "\", \"" + op.getField() + "\")" + addFieldOpOptional(op) + ";";
+    }
+
+    private String addFieldOpOptional(AddFieldOperation op) {
+        return "\n"
+               + "    .notNull(" + op.isNotNull() + ")\n"
+               + "    .sqlType(\"" + op.getSqlType() + "\")";
+    }
+
+    private String addForeignKeyOp(AddForeignKeyOperation op) {
+        imports.add(List.class);
+        imports.add(ForeignKeyConstraint.class);
+        imports.add(ForeignKeyConstraint.Action.class);
+        return "mb.addForeignKey(\"" + op.getName() + "\",\n"
+               + "                 \"" + op.getTable() + "\",\n"
+               + "                 List.of(" + op.getFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "),\n"
+               + "                 \"" + op.getReferencedTable() + "\",\n"
+               + "                 List.of(" + op.getReferencedFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "),\n"
+               + "                 ForeignKeyConstraint.Action." + op.getOnUpdate().name() + ",\n"
+               + "                 ForeignKeyConstraint.Action." + op.getOnDelete().name() + ");";
+    }
+
+    private String addIndexOp(AddIndexOperation op) {
+        imports.add(List.class);
+        return "mb.addIndex(\"" + op.getName() + "\",\n"
+               + "            \"" + op.getTable() + "\",\n"
+               + "            List.of(" + op.getFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "));";
+    }
+
+    private String addKeyOp(AddKeyOperation op) {
+        imports.add(List.class);
+        return "mb.addKey(\"" + op.getName() + "\",\n"
+               + "            \"" + op.getTable() + "\",\n"
+               + "            List.of(" + op.getFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "));";
+    }
+
+    private String addPrimaryKeyOp(AddPrimaryKeyOperation op) {
+        imports.add(List.class);
+        return "mb.addPrimaryKey(\"" + op.getName() + "\",\n"
+               + "            \"" + op.getTable() + "\",\n"
+               + "            List.of(" + op.getFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "));";
+    }
+
+    private String addTableOp(AddTableOperation op) {
+        imports.add(List.class);
+        imports.add(AddFieldOperation.class);
+        imports.add(AddFieldOperation.Builder.class);
+        return "mb.addTable(\"" + op.getTable() + "\", List.of(\n"
+               + op.getFields().stream()
+                       /**/.map(f -> "    new AddFieldOperation.Builder(\"" + op.getTable() + "\", \"" + f.build().getField() + "\")" + addFieldOpOptional(f.build()).replace("\n", "\n    "))
+                       /**/.collect(Collectors.joining(",\n")) + "\n"
+               + "));";
+    }
+
+    private String addUniqueKeyOp(AddUniqueKeyOperation op) {
+        imports.add(List.class);
+        return "mb.addUniqueKey(\"" + op.getName() + "\",\n"
+               + "            \"" + op.getTable() + "\",\n"
+               + "            List.of(" + op.getFields().stream().map(e -> "\"" + e + "\"").collect(Collectors.joining(", ")) + "));";
+    }
+
+    private String dropConstraintOp(DropConstraintOperation op) {
+        return "mb.dropConstraint(\"" + op.getTable() + "\", \"" + op.getName() + "\");";
+    }
+
+    private String dropFieldOp(DropFieldOperation op) {
+        return "mb.dropField(\"" + op.getTable() + "\", \"" + op.getField() + "\");";
+    }
+
+    private String dropTableOp(DropTableOperation op) {
+        return "mb.dropTable(\"" + op.getTable() + "\");";
+    }
+
+    private String renameFieldOp(RenameFieldOperation op) {
+        return "mb.renameField(\"" + op.getTable() + "\", \"" + op.getOldName() + "\", \"" + op.getNewName() + "\");";
+    }
+
+    private String renameTableOp(RenameTableOperation op) {
+        return "mb.renameTable(\"" + op.getOldName() + "\", \"" + op.getNewName() + "\");";
+    }
+
+    private String updateField(UpdateFieldOperation op) {
+        return "mb.updateField(\"" + op.getTable() + "\", \"" + op.getField() + "\")\n"
+               + (op.getNewName() != null ? "    .newName(\"" + op.getNewName() + "\")\n" : "")
+               + "    .notNull(" + op.isNotNull() + ")\n"
+               + "    .sqlType(" + op.getSqlType() + ");";
+    }
+}

src/main/java/jef/model/migration/creator/MigrationCreator.java

@@ -0,0 +1,487 @@
+package jef.model.migration.creator;
+
+import jef.model.DbField;
+import jef.model.ModelBuilder;
+import jef.model.ModelException;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.constraints.IndexConstraint;
+import jef.model.constraints.KeyConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
+import jef.model.migration.operation.AddFieldOperation;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddIndexOperation;
+import jef.model.migration.operation.AddKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddTableOperation;
+import jef.model.migration.operation.AddUniqueKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropFieldOperation;
+import jef.model.migration.operation.DropTableOperation;
+import jef.model.migration.operation.MigrationOperation;
+import jef.model.migration.operation.RenameFieldOperation;
+import jef.model.migration.operation.RenameTableOperation;
+import jef.model.migration.operation.UpdateFieldOperation;
+import jef.util.Check;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class MigrationCreator {
+    private static final String ILLEGAL_CHARACTERS = "\"'`,.";//TODO also validate this in modelbuilder/dbentity/dbfield
+
+    public Result createMigration(ModelBuilder from, ModelBuilder to, String name, String packageName, String currentSnapshotJava) {
+        var result = new Result();
+
+        //create pre-migration model snapshot class
+        result = generatePreMigrationSnapshot(name, packageName, currentSnapshotJava, result);
+
+        //create migration
+        result = generateMigration(from, to, name, packageName, result);
+
+        //create current model snapshot class
+        result = generatePostMigrationSnapshot(to, packageName, result);
+        return result;
+    }
+
+    private Result generatePreMigrationSnapshot(String name, String packageName, String currentSnapshotJava, Result result) {
+        String preMigrationSnapshot;
+        if (currentSnapshotJava == null || currentSnapshotJava.isBlank()) {
+            preMigrationSnapshot = generateModelBuilderJava(new ModelBuilder(), name, packageName);
+        } else {
+            preMigrationSnapshot = currentSnapshotJava.replace("CurrentSnapshot", name + "Snapshot");
+        }
+        result.setMigrationSnapshot(preMigrationSnapshot);
+        return result;
+    }
+
+    private Result generatePostMigrationSnapshot(ModelBuilder to, String packageName, Result result) {
+        result.setCurrentSnapshot(generateModelBuilderJava(to, "Current", packageName));
+        return result;
+    }
+
+    private String generateModelBuilderJava(ModelBuilder mb, String name, String packageName) {
+        return new ModelBuilderGenerator(mb, name, packageName).generate().getJava();
+    }
+
+    private Result generateMigration(ModelBuilder from, ModelBuilder to, String name, String packageName, Result result) {
+        //check for illegal characters
+        for (var entity : to.getEntities()) {
+            if (entity.getName().matches("[" + ILLEGAL_CHARACTERS + "]")) {
+                throw new ModelException("Entity " + entity.getType().getSimpleName() + " has illegal characters in its name: " + entity.getName());
+            }
+            for (var field : entity.getFields()) {
+                if (field.getName().matches("[" + ILLEGAL_CHARACTERS + "]")) {
+                    throw new ModelException("Field " + entity.getType().getSimpleName() + "::" + field.getField().getName() + " has illegal characters in its name: " + entity.getName());
+                }
+            }
+        }
+
+        //reduce model builders to changes
+        var mcd = new ModelChangeDetector(from, to).detect();
+        var fromReduced = mcd.getFrom();
+        var toReduced = mcd.getTo();
+
+        //create migration steps
+        var migrationUpOps = new ArrayList<MigrationOperation.Builder>();
+        var migrationDownOps = new ArrayList<MigrationOperation.Builder>();
+
+        generateMigrationSteps(fromReduced, toReduced, from, to, migrationUpOps);
+        generateMigrationSteps(toReduced, fromReduced, to, from, migrationDownOps);
+
+        var builtUpOps = migrationUpOps.stream().map(e -> e.build()).toList();
+        var builtDownOps = migrationDownOps.stream().map(e -> e.build()).toList();
+
+        result.setMigration(new MigrationBuilderGenerator(builtUpOps, builtDownOps, name, packageName).generate().getJava());
+        result.setStepsUp(builtUpOps);
+        result.setStepsDown(builtDownOps);
+
+        return result;
+    }
+
+    private void generateMigrationSteps(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        //key drop
+        addForeignKeyDropGeneration(fromReduced, toReduced, from, to, steps);
+        addPrimaryKeyDropGeneration(fromReduced, toReduced, from, to, steps);
+        addUniqueKeyDropGeneration(fromReduced, toReduced, from, to, steps);
+        addKeyDropGeneration(fromReduced, toReduced, from, to, steps);
+        addIndexDropGeneration(fromReduced, toReduced, from, to, steps);
+
+        //table
+        addTableDropGeneration(fromReduced, toReduced, from, to, steps);
+        addTableRenameGeneration(fromReduced, toReduced, from, to, steps);
+        addTableAddGeneration(fromReduced, toReduced, from, to, steps);
+
+        //fields
+        addFieldAddRenameUpdateDropGeneration(fromReduced, toReduced, from, to, steps);
+
+        //key add
+        addPrimaryKeyAddGeneration(fromReduced, toReduced, from, to, steps);
+        addForeignKeyAddGeneration(fromReduced, toReduced, from, to, steps);
+        addUniqueKeyAddGeneration(fromReduced, toReduced, from, to, steps);
+        addKeyAddGeneration(fromReduced, toReduced, from, to, steps);
+        addIndexAddGeneration(fromReduced, toReduced, from, to, steps);
+    }
+
+    private void addTableAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var fromEntity = fromReduced.getEntity(toEntity.getTypeName());
+
+            //new entity
+            if (fromEntity == null) {
+                steps.add(new AddTableOperation.Builder(
+                        toEntity.getName(),
+                        toEntity.getFields().stream()
+                                .filter(DbField::isDatabaseField)
+                                .map(e -> new AddFieldOperation.Builder(toEntity.getName(), e.getName())
+                                        .notNull(e.isNotNull())
+                                        .sqlType("TODO"))
+                                .toList()
+                ));
+            }
+        }
+    }
+
+    private void addTableRenameGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var fromEntity = fromReduced.getEntity(toEntity.getTypeName());
+            // entity added
+            if (fromEntity == null) {
+                continue;
+            }
+
+            //entity rename
+            if (!fromEntity.getName().equals(toEntity.getName())) {
+                steps.add(new RenameTableOperation.Builder(fromEntity.getName(), toEntity.getName()));
+            }
+        }
+    }
+
+    private void addTableDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var toEntity = toReduced.getEntity(fromEntity.getTypeName());
+            if (toEntity == null) {
+                steps.add(new DropTableOperation.Builder(fromEntity.getName()));
+            }
+        }
+    }
+
+    private void addFieldAddRenameUpdateDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var fromEntity = fromReduced.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+
+            //entity added -> nothing to do here
+            if (fromEntity == null) {
+                continue;
+            }
+
+            var remainingFromFields = new ArrayList<>(fromEntity.getFields());
+            var remainingToFields = new ArrayList<>(toEntity.getFields());
+
+            var handledFrom = new ArrayList<DbField<?>>();
+            var handledTo = new ArrayList<DbField<?>>();
+
+            //fields with same name but different type parameters
+            for (DbField<?> toField : toEntity.getFields()) {
+                var fromField = fromEntity.getFields().stream().filter(e -> e.getName().equals(toField.getName())).findFirst().orElse(null);
+                if (fromField != null) {
+                    handledFrom.add(fromField);
+                    handledTo.add(toField);
+                    //this assumes the reduced ModelBuilders exclude exactly matching entities
+                    steps.add(new UpdateFieldOperation.Builder(toField.getEntity().getName(), toField.getName())
+                                      .notNull(toField.isNotNull()));
+                }
+            }
+
+            //fields with different name but same type parameters
+            remainingFromFields.removeAll(handledFrom);
+            remainingToFields.removeAll(handledTo);
+
+            var map = new ArrayList<FieldCompare>();
+            for (DbField<?> toField : remainingToFields) {
+                for (DbField<?> FromField : remainingFromFields) {
+                    map.add(new FieldCompare(FromField, toField));
+                }
+            }
+            map.removeIf(e -> e.getSimilarity() <= 0);
+            map.sort(Comparator.comparingInt(FieldCompare::getSimilarity).reversed());
+
+            for (FieldCompare compare : map) {
+                var toField = compare.getTo();
+                var fromField = compare.getFrom();
+                if (handledFrom.contains(fromField) || handledTo.contains(toField)) {
+                    continue;
+                }
+
+                handledFrom.add(fromField);
+                handledTo.add(toField);
+                steps.add(new RenameFieldOperation.Builder(toField.getEntity().getName(), fromField.getName(), toField.getName()));
+            }
+
+            //drop
+            remainingFromFields.removeAll(handledFrom);
+            remainingToFields.removeAll(handledTo);
+            for (DbField<?> fromField : remainingFromFields) {
+                var toField = remainingToFields.stream().filter(e -> e.getName().equals(fromField.getName())).findFirst().orElse(null);
+                if (toField == null) {
+                    handledFrom.add(fromField);
+                    steps.add(new DropFieldOperation.Builder(fromField.getEntity().getName(), fromField.getName()));
+                }
+            }
+
+            //add
+            remainingFromFields.removeAll(handledFrom);
+            remainingToFields.removeAll(handledTo);
+            for (DbField<?> toField : remainingToFields) {
+                var fromField = remainingFromFields.stream().filter(e -> e.getName().equals(toField.getName())).findFirst().orElse(null);
+                if (fromField == null) {
+                    handledTo.add(toField);
+                    steps.add(new AddFieldOperation.Builder(toField.getEntity().getName(), toField.getName())
+                                      .notNull(toField.isNotNull()));
+                }
+            }
+        }
+    }
+
+    private void addPrimaryKeyAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var originalEntity = to.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = toEntity.getFields();
+            var involvedForeignKeys = originalEntity.getPrimaryKey() != null
+                                      && originalEntity.getPrimaryKey().getFields().stream().anyMatch(involvedFields::contains);
+            if (involvedForeignKeys) {
+                steps.add(new AddPrimaryKeyOperation.Builder(
+                        originalEntity.getPrimaryKey().getName(),
+                        originalEntity.getPrimaryKey().getEntity().getName(),
+                        originalEntity.getPrimaryKey().getFields().stream().map(DbField::getName).collect(Collectors.toList())));
+            }
+        }
+    }
+
+    private void addForeignKeyAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var originalEntity = to.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = toEntity.getFields();
+            var involvedForeignKeys = originalEntity.getForeignKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || toEntity.getForeignKeys().contains(e))
+                    .toList();
+            for (ForeignKeyConstraint foreignKey : involvedForeignKeys) {
+                steps.add(new AddForeignKeyOperation.Builder(
+                        foreignKey.getName(),
+                        foreignKey.getEntity().getName(),
+                        foreignKey.getFields().stream().map(DbField::getName).collect(Collectors.toList()),
+                        foreignKey.getReferencedEntity().getName(),
+                        foreignKey.getReferencedFields().stream().map(DbField::getName).collect(Collectors.toList()),
+                        foreignKey.getOnUpdate(), foreignKey.getOnDelete()));
+            }
+        }
+    }
+
+    private void addUniqueKeyAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var originalEntity = to.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = toEntity.getFields();
+            var involvedUniqueKeys = originalEntity.getUniqueKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || toEntity.getUniqueKeys().contains(e))
+                    .toList();
+            for (UniqueKeyConstraint uniqueKey : involvedUniqueKeys) {
+                steps.add(new AddUniqueKeyOperation.Builder(
+                        uniqueKey.getName(),
+                        uniqueKey.getEntity().getName(),
+                        uniqueKey.getFields().stream().map(DbField::getName).collect(Collectors.toList())));
+            }
+        }
+    }
+
+    private void addKeyAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var originalEntity = to.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = toEntity.getFields();
+            var involvedKeys = originalEntity.getKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || toEntity.getKeys().contains(e))
+                    .toList();
+            for (KeyConstraint key : involvedKeys) {
+                steps.add(new AddKeyOperation.Builder(
+                        key.getName(),
+                        key.getEntity().getName(),
+                        key.getFields().stream().map(DbField::getName).collect(Collectors.toList())));
+            }
+        }
+    }
+
+    private void addIndexAddGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var toEntity : toReduced.getEntities()) {
+            var originalEntity = to.getEntities().stream().filter(e -> e.getName().equals(toEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = toEntity.getFields();
+            var involvedIndexes = originalEntity.getIndexes().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || toEntity.getIndexes().contains(e))
+                    .toList();
+            for (IndexConstraint index : involvedIndexes) {
+                steps.add(new AddIndexOperation.Builder(
+                        index.getName(),
+                        index.getEntity().getName(),
+                        index.getFields().stream().map(DbField::getName).collect(Collectors.toList())));
+            }
+        }
+    }
+
+    private void addPrimaryKeyDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var originalEntity = from.getEntities().stream().filter(e -> e.getName().equals(fromEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = fromEntity.getFields();
+            if (originalEntity.getPrimaryKey() == null) {
+                continue;
+            }
+            var isPrimaryKeyInvolved = originalEntity.getPrimaryKey().getFields().stream().anyMatch(involvedFields::contains);
+            if (isPrimaryKeyInvolved) {
+                //drop all referencing foreign keys
+                from.getEntities().stream().flatMap(e -> e.getForeignKeys().stream())
+                        .filter(foreignKey -> foreignKey.getReferencedEntity() == fromEntity
+                                              && foreignKey.getReferencedFields().stream().anyMatch(involvedFields::contains))
+                        .forEach(foreignKey -> steps.add(new DropConstraintOperation.Builder(foreignKey.getName(), fromEntity.getName())));
+
+                //drop primary
+                steps.add(new DropConstraintOperation.Builder(originalEntity.getPrimaryKey().getName(), fromEntity.getName()));
+            }
+        }
+    }
+
+    private void addForeignKeyDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var originalEntity = from.getEntities().stream().filter(e -> e.getName().equals(fromEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = fromEntity.getFields();
+            var involvedForeignKeys = originalEntity.getForeignKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || fromEntity.getForeignKeys().contains(e))
+                    .toList();
+            for (ForeignKeyConstraint foreignKey : involvedForeignKeys) {
+                steps.add(new DropConstraintOperation.Builder(foreignKey.getName(), fromEntity.getName()));
+            }
+        }
+
+        //        for (var fromEntity : from.getEntities()) {
+//            var toEntity = to.getEntity(fromEntity.getType());
+//
+//            //foreign keys
+//            for (var foreignKey : fromEntity.getForeignKeys()) {
+//                if (toEntity == null || toEntity.getForeignKeys().stream().noneMatch(fk -> compareForeignKey(foreignKey, fk))) {
+//                    migrationUpOps.add(new DropConstraintOperation.Builder(foreignKey.getName(), fromEntity.getName()));
+//                }
+//            }
+//        }
+    }
+
+    private void addUniqueKeyDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var originalEntity = from.getEntities().stream().filter(e -> e.getName().equals(fromEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = fromEntity.getFields();
+            var involvedForeignKeys = originalEntity.getUniqueKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || fromEntity.getUniqueKeys().contains(e))
+                    .toList();
+            for (UniqueKeyConstraint uniqueKey : involvedForeignKeys) {
+                steps.add(new DropConstraintOperation.Builder(uniqueKey.getName(), fromEntity.getName()));
+            }
+        }
+
+        //        for (var fromEntity : from.getEntities()) {
+//            var toEntity = to.getEntity(fromEntity.getType());
+//
+//            //unique keys
+//            for (var uniqueKey : fromEntity.getUniqueKeys()) {
+//                if (toEntity == null || toEntity.getUniqueKeys().stream().noneMatch(uk -> compareConstraint(uniqueKey, uk))) {
+//                    steps.add(new DropConstraintOperation.Builder(uniqueKey.getName(), fromEntity.getName()));
+//                }
+//            }
+//        }
+    }
+
+    private void addKeyDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var originalEntity = from.getEntities().stream().filter(e -> e.getName().equals(fromEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = fromEntity.getFields();
+            var involvedForeignKeys = originalEntity.getKeys().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || fromEntity.getKeys().contains(e))
+                    .toList();
+            for (KeyConstraint key : involvedForeignKeys) {
+                steps.add(new DropConstraintOperation.Builder(key.getName(), fromEntity.getName()));
+            }
+        }
+
+//        for (var fromEntity : from.getEntities()) {
+//            var toEntity = to.getEntity(fromEntity.getType());
+//
+//            //keys
+//            for (var key : fromEntity.getKeys()) {
+//                if (toEntity == null || toEntity.getKeys().stream().noneMatch(k -> compareConstraint(key, k))) {
+//                    migrationUpOps.add(new DropConstraintOperation.Builder(key.getName(), fromEntity.getName()));
+//                }
+//            }
+//        }
+    }
+
+    private void addIndexDropGeneration(ModelBuilder fromReduced, ModelBuilder toReduced, ModelBuilder from, ModelBuilder to, List<MigrationOperation.Builder> steps) {
+        for (var fromEntity : fromReduced.getEntities()) {
+            var originalEntity = from.getEntities().stream().filter(e -> e.getName().equals(fromEntity.getName())).findFirst().orElse(null);
+            Check.notNull(originalEntity, "originalEntity"); //may never be null
+            var involvedFields = fromEntity.getFields();
+            var involvedForeignKeys = originalEntity.getIndexes().stream()
+                    .filter(e -> e.getFields().stream().anyMatch(involvedFields::contains) || fromEntity.getIndexes().contains(e))
+                    .toList();
+            for (IndexConstraint foreignKey : involvedForeignKeys) {
+                steps.add(new DropConstraintOperation.Builder(foreignKey.getName(), fromEntity.getName()));
+            }
+        }
+
+//        for (var fromEntity : from.getEntities()) {
+//            var toEntity = to.getEntity(fromEntity.getType());
+//
+//            //indexes
+//            for (var index : fromEntity.getIndexes()) {
+//                if (toEntity == null || toEntity.getIndexes().stream().noneMatch(i -> compareConstraint(index, i))) {
+//                    steps.add(new DropConstraintOperation.Builder(index.getName(), fromEntity.getName()));
+//                }
+//            }
+//        }
+    }
+
+    @Getter
+    @Setter(AccessLevel.PACKAGE)
+    @NoArgsConstructor(access = AccessLevel.PACKAGE)
+    public static class Result {
+        private List<MigrationOperation> stepsUp = new ArrayList<>();
+        private List<MigrationOperation> stepsDown = new ArrayList<>();
+        private String migration = "";
+        private String migrationSnapshot = "";
+        private String currentSnapshot = "";
+    }
+
+    @Getter
+    private class FieldCompare {
+        private final DbField<?> from;
+        private final DbField<?> to;
+        private final int similarity;
+
+        public FieldCompare(DbField<?> from, DbField<?> to) {
+            this.from = from;
+            this.to = to;
+            this.similarity = compute();
+        }
+
+        private int compute() {
+            return from.equalsExceptName(to) ? 1 : 0;
+        }
+    }
+}

src/main/java/jef/model/migration/creator/ModelBuilderGenerator.java

@@ -0,0 +1,124 @@
+package jef.model.migration.creator;
+
+import jef.model.DbContext;
+import jef.model.DbEntity;
+import jef.model.DbField;
+import jef.model.ModelBuilder;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.constraints.IndexConstraint;
+import jef.model.constraints.KeyConstraint;
+import jef.model.constraints.PrimaryKeyConstraint;
+import jef.model.constraints.UniqueKeyConstraint;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+public class ModelBuilderGenerator {
+    private final ModelBuilder mb;
+    private final String name;
+    private final String packageName;
+
+    private final Set<Class<?>> imports = new HashSet<>();
+    @Getter
+    private String java = null;
+
+    public ModelBuilderGenerator generate() {
+        if (java == null) {
+            java = generateModelBuilderJava();
+        }
+        return this;
+    }
+
+    private String generateModelBuilderJava() {
+        var indent = "        ";
+        imports.add(DbContext.class);
+        imports.add(ModelBuilder.class);
+        imports.add(DbEntity.class);
+        var java = ""
+                   + "public class " + name + "Snapshot extends DbContext {\n"
+                   + "    @Override\n"
+                   + "    public void onModelCreate(ModelBuilder mb) {\n"
+                   + indent + "DbEntity entity;\n"
+                   + indent + "DbEntity referencedEntity;\n";
+        for (DbEntity<? extends SerializableObject> entity : mb.getEntities()) {
+            java += indent + "entity = mb.getOrCreateEntity(\"" + entity.getTypeName() + "\");\n"
+                    + indent + "entity.setName(\"" + entity.getName() + "\");\n";
+            for (DbField<?> field : entity.getFields()) {
+                java += indent + "entity.getOrCreateField(\"" + field.getName() + "\", \"" + field.getTypeName() + "\")"
+                        + (field.isNotNull() ? "\n" + indent + "    .setNotNull(true)" : "")
+                        + "\n" + indent + "    .setDatabaseField(" + field.isDatabaseField() + ")"
+                        + "\n" + indent + "    .setModelField(" + field.isModelField() + ")"
+                        + ";\n";
+            }
+            if (entity.getPrimaryKey() != null) {
+                imports.add(List.class);
+                imports.add(PrimaryKeyConstraint.class);
+                java += indent + "entity.setPrimaryKey(new PrimaryKeyConstraint(entity, List.of(\n"
+                        + indent + "        " + entity.getPrimaryKey().getFields().stream().map(f -> "entity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        ")) + "\n"
+                        + indent + "    )));\n";
+            }
+            java += "\n";
+        }
+        for (DbEntity<? extends SerializableObject> entity : mb.getEntities()) {
+            if (entity.getForeignKeys().isEmpty() && entity.getForeignKeys().isEmpty() && entity.getForeignKeys().isEmpty() && entity.getForeignKeys().isEmpty()) {
+                continue;
+            }
+
+            java += indent + "entity = mb.getOrCreateEntity(\"" + entity.getTypeName() + "\");\n";
+            for (ForeignKeyConstraint foreignKey : entity.getForeignKeys()) {
+                imports.add(List.class);
+                imports.add(ForeignKeyConstraint.class);
+                imports.add(ForeignKeyConstraint.Action.class);
+                java += indent + "referencedEntity = mb.getEntity(\"" + foreignKey.getReferencedEntity().getTypeName() + "\");\n"
+                        + indent + "entity.addForeignKey(new ForeignKeyConstraint(entity, List.of(\n"
+                        + indent + "        " + foreignKey.getFields().stream().map(f -> "entity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        " + indent)) + "\n"
+                        + indent + "    ),\n"
+                        + indent + "    referencedEntity, List.of(\n"
+                        + indent + "        " + foreignKey.getReferencedFields().stream().map(f -> "referencedEntity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        " + indent)) + "\n"
+                        + indent + "    ),\n"
+                        + indent + "    ForeignKeyConstraint.Action." + foreignKey.getOnUpdate().name() + ", ForeignKeyConstraint.Action." + foreignKey.getOnDelete().name() + "));\n";
+            }
+            for (UniqueKeyConstraint uniqueKey : entity.getUniqueKeys()) {
+                imports.add(List.class);
+                imports.add(UniqueKeyConstraint.class);
+                java += indent + "entity.addUniqueKey(new UniqueKeyConstraint(entity, List.of(\n"
+                        + indent + "        " + uniqueKey.getFields().stream().map(f -> "entity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        " + indent)) + "\n"
+                        + indent + "    )));\n";
+            }
+            for (KeyConstraint key : entity.getKeys()) {
+                imports.add(List.class);
+                imports.add(KeyConstraint.class);
+                java += indent + "entity.addKey(new KeyConstraint(entity, List.of(\n"
+                        + indent + "        " + key.getFields().stream().map(f -> "entity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        " + indent)) + "\n"
+                        + indent + "    )));\n";
+            }
+            for (IndexConstraint index : entity.getIndexes()) {
+                imports.add(List.class);
+                imports.add(IndexConstraint.class);
+                java += indent + "entity.addIndex(new IndexConstraint(entity, List.of(\n"
+                        + indent + "        " + index.getFields().stream().map(f -> "entity.getField(\"" + f.getName() + "\")").collect(Collectors.joining(",\n        " + indent)) + "\n"
+                        + indent + "    )));\n";
+            }
+        }
+        java += "    }\n"
+                + "}\n";
+
+        //imports
+        var normalImports = imports.stream().filter(e -> !e.getName().startsWith("java")).sorted(Comparator.comparing(Class::getName, String.CASE_INSENSITIVE_ORDER)).toList();
+        var javaImports = imports.stream().filter(e -> e.getName().startsWith("java")).sorted(Comparator.comparing(Class::getName, String.CASE_INSENSITIVE_ORDER)).toList();
+
+        //finalize
+        java = "package " + packageName + ";\n\n"
+               + normalImports.stream().map(e -> "import " + e.getName().replace("$", ".") + ";").collect(Collectors.joining("\n")) + "\n\n"
+               + javaImports.stream().map(e -> "import " + e.getName().replace("$", ".") + ";").collect(Collectors.joining("\n")) + "\n\n"
+               + java;
+        return java;
+    }
+}

src/main/java/jef/model/migration/creator/ModelChangeDetector.java

@@ -0,0 +1,116 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import jef.util.Check;
+import lombok.Getter;
+
+import java.util.Objects;
+
+@Getter
+public class ModelChangeDetector {
+    private final ModelBuilder from;
+    private final ModelBuilder to;
+
+    public ModelChangeDetector(ModelBuilder from, ModelBuilder to) {
+        this.from = Check.notNull(from, "from").clone();
+        this.to = Check.notNull(to, "to").clone();
+    }
+
+    public ModelChangeDetector detect() {
+        extractChanges();
+        return this;
+    }
+
+    private void extractChanges() {
+        extractChangesFromTo(from, to);
+        extractChangesFromTo(to, from);
+
+        for (int i = 0; i < to.getEntities().size(); i++) {
+            var toEntity = to.getEntities().get(i);
+            var fromEntity = from.getEntities().stream().filter(e -> e.getTypeName().equals(toEntity.getTypeName())).findFirst().orElse(null);
+            if (fromEntity != null) {
+                //entity empty
+                if (toEntity.getName().equals(fromEntity.getName())
+                    && toEntity.getFields().isEmpty()
+                    && toEntity.getPrimaryKey() == null
+                    && toEntity.getForeignKeys().isEmpty()
+                    && toEntity.getUniqueKeys().isEmpty()
+                    && toEntity.getKeys().isEmpty()
+                    && toEntity.getIndexes().isEmpty()
+                    && fromEntity.getFields().isEmpty()
+                    && fromEntity.getPrimaryKey() == null
+                    && fromEntity.getForeignKeys().isEmpty()
+                    && fromEntity.getUniqueKeys().isEmpty()
+                    && fromEntity.getKeys().isEmpty()
+                    && fromEntity.getIndexes().isEmpty()) {
+                    to.dropEntity(toEntity);
+                    from.dropEntity(fromEntity);
+                    i--;
+                }
+            }
+        }
+    }
+
+    private void extractChangesFromTo(ModelBuilder from, ModelBuilder to) {
+        for (int i = 0; i < to.getEntities().size(); i++) {
+            var toEntity = to.getEntities().get(i);
+            var fromEntity = from.getEntities().stream().filter(e -> e.getTypeName().equals(toEntity.getTypeName())).findFirst().orElse(null);
+            if (fromEntity != null) {
+                for (int j = 0; j < toEntity.getFields().size(); j++) {
+                    var toField = toEntity.getFields().get(j);
+                    var fromField = fromEntity.getFields().stream().filter(e -> e.equals(toField)).findFirst().orElse(null);
+                    if (fromField != null) {
+                        toEntity.dropField(toField);
+                        fromEntity.dropField(fromField);
+                        j--;
+                    }
+                }
+
+                if (Objects.equals(fromEntity.getPrimaryKey(), toEntity.getPrimaryKey())) {
+                    fromEntity.setPrimaryKey(null);
+                    toEntity.setPrimaryKey(null);
+                }
+
+                for (int j = 0; j < toEntity.getForeignKeys().size(); j++) {
+                    var toFk = toEntity.getForeignKeys().get(j);
+                    var fromFk = fromEntity.getForeignKeys().stream().filter(e -> e.equals(toFk)).findFirst().orElse(null);
+                    if (fromFk != null) {
+                        toEntity.dropForeignKey(toFk);
+                        fromEntity.dropForeignKey(fromFk);
+                        j--;
+                    }
+                }
+
+                for (int j = 0; j < toEntity.getUniqueKeys().size(); j++) {
+                    var toUnique = toEntity.getUniqueKeys().get(j);
+                    var fromUnique = fromEntity.getUniqueKeys().stream().filter(e -> e.equals(toUnique)).findFirst().orElse(null);
+                    if (fromUnique != null) {
+                        toEntity.dropUniqueKey(toUnique);
+                        fromEntity.dropUniqueKey(fromUnique);
+                        j--;
+                    }
+                }
+
+                for (int j = 0; j < toEntity.getKeys().size(); j++) {
+                    var toKey = toEntity.getKeys().get(j);
+                    var fromKey = fromEntity.getKeys().stream().filter(e -> e.equals(toKey)).findFirst().orElse(null);
+                    if (fromKey != null) {
+                        toEntity.dropKey(toKey);
+                        fromEntity.dropKey(fromKey);
+                        j--;
+                    }
+                }
+
+                for (int j = 0; j < toEntity.getIndexes().size(); j++) {
+                    var toIx = toEntity.getIndexes().get(j);
+                    var fromIx = fromEntity.getIndexes().stream().filter(e -> e.equals(toIx)).findFirst().orElse(null);
+                    if (fromIx != null) {
+                        toEntity.dropIndex(toIx);
+                        fromEntity.dropIndex(fromIx);
+                        j--;
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddFieldOperation.java

@@ -0,0 +1,41 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class AddFieldOperation implements MigrationOperation {
+    protected final String table;
+    protected final String field;
+    protected final String sqlType;
+    protected final boolean notNull;
+
+    public static class Builder implements MigrationOperation.Builder<AddFieldOperation> {
+        protected final String table;
+        protected final String field;
+        protected String sqlType;
+        protected boolean notNull;
+
+        public Builder(String table, String field) {
+            this.table = table;
+            this.field = field;
+        }
+
+        public Builder sqlType(String sqlType) {
+            this.sqlType = sqlType;
+            return this;
+        }
+
+        public Builder notNull(boolean notNull) {
+            this.notNull = notNull;
+            return this;
+        }
+
+        public AddFieldOperation build() {
+            return new AddFieldOperation(table, field, sqlType, notNull);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddForeignKeyOperation.java

@@ -0,0 +1,44 @@
+package jef.model.migration.operation;
+
+import jef.model.constraints.ForeignKeyConstraint;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+@AllArgsConstructor
+public class AddForeignKeyOperation implements MigrationOperation {
+    private final String name;
+    private final String table;
+    private final List<String> fields;
+    private final String referencedTable;
+    private final List<String> referencedFields;
+    private final ForeignKeyConstraint.Action onUpdate;
+    private final ForeignKeyConstraint.Action onDelete;
+
+    public static class Builder implements MigrationOperation.Builder<AddForeignKeyOperation> {
+        private final String name;
+        private final String table;
+        private final List<String> fields;
+        private final String referencedTable;
+        private final List<String> referencedFields;
+        private final ForeignKeyConstraint.Action onUpdate;
+        private final ForeignKeyConstraint.Action onDelete;
+
+        public Builder(String name, String table, List<String> fields, String referencedTable, List<String> referencedFields, ForeignKeyConstraint.Action onUpdate, ForeignKeyConstraint.Action onDelete) {
+            this.name = name;
+            this.table = table;
+            this.fields = fields;
+            this.referencedTable = referencedTable;
+            this.referencedFields = referencedFields;
+            this.onUpdate = onUpdate;
+            this.onDelete = onDelete;
+        }
+
+        public AddForeignKeyOperation build() {
+            return new AddForeignKeyOperation(name, table, fields, referencedTable, referencedFields, onUpdate, onDelete);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddIndexOperation.java

@@ -0,0 +1,23 @@
+package jef.model.migration.operation;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+public class AddIndexOperation extends AddKeyOperationBase {
+    public AddIndexOperation(String name, String table, List<String> fields) {
+        super(name, table, fields);
+    }
+
+    public static class Builder extends AddKeyOperationBase.Builder<AddIndexOperation> {
+        public Builder(String name, String table, List<String> fields) {
+            super(name, table, fields);
+        }
+
+        public AddIndexOperation build() {
+            return new AddIndexOperation(name, table, fields);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddKeyOperation.java

@@ -0,0 +1,23 @@
+package jef.model.migration.operation;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+public class AddKeyOperation extends AddKeyOperationBase {
+    public AddKeyOperation(String name, String table, List<String> fields) {
+        super(name, table, fields);
+    }
+
+    public static class Builder extends AddKeyOperationBase.Builder<AddKeyOperation> {
+        public Builder(String name, String table, List<String> fields) {
+            super(name, table, fields);
+        }
+
+        public AddKeyOperation build() {
+            return new AddKeyOperation(name, table, fields);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddKeyOperationBase.java

@@ -0,0 +1,26 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public abstract class AddKeyOperationBase implements MigrationOperation {
+    protected final String name;
+    protected final String table;
+    protected final List<String> fields;
+
+    public abstract static class Builder<T extends AddKeyOperationBase> implements MigrationOperation.Builder<T> {
+        protected final String name;
+        protected final String table;
+        protected final List<String> fields;
+
+        public Builder(String name, String table, List<String> fields) {
+            this.name = name;
+            this.table = table;
+            this.fields = fields;
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddPrimaryKeyOperation.java

@@ -0,0 +1,23 @@
+package jef.model.migration.operation;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+public class AddPrimaryKeyOperation extends AddKeyOperationBase {
+    public AddPrimaryKeyOperation(String name, String table, List<String> fields) {
+        super(name, table, fields);
+    }
+
+    public static class Builder extends AddKeyOperationBase.Builder<AddPrimaryKeyOperation> {
+        public Builder(String name, String table, List<String> fields) {
+            super(name, table, fields);
+        }
+
+        public AddPrimaryKeyOperation build() {
+            return new AddPrimaryKeyOperation(name, table, fields);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddTableOperation.java

@@ -0,0 +1,28 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+@AllArgsConstructor
+public class AddTableOperation implements MigrationOperation {
+    private final String table;
+    private final List<AddFieldOperation.Builder> fields;
+
+    public static class Builder implements MigrationOperation.Builder<AddTableOperation> {
+        private final String table;
+        private final List<AddFieldOperation.Builder> fields;
+
+        public Builder(String table, List<AddFieldOperation.Builder> fields) {
+            this.table = table;
+            this.fields = fields;
+        }
+
+        public AddTableOperation build() {
+            return new AddTableOperation(table, fields);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/AddUniqueKeyOperation.java

@@ -0,0 +1,23 @@
+package jef.model.migration.operation;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Getter
+public class AddUniqueKeyOperation extends AddKeyOperationBase {
+    public AddUniqueKeyOperation(String name, String table, List<String> fields) {
+        super(name, table, fields);
+    }
+
+    public static class Builder extends AddKeyOperationBase.Builder<AddUniqueKeyOperation> {
+        public Builder(String name, String table, List<String> fields) {
+            super(name, table, fields);
+        }
+
+        public AddUniqueKeyOperation build() {
+            return new AddUniqueKeyOperation(name, table, fields);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/DropConstraintOperation.java

@@ -0,0 +1,27 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class DropConstraintOperation implements MigrationOperation {
+    private final String name;
+    private final String table;
+
+    public static class Builder implements MigrationOperation.Builder<DropConstraintOperation> {
+        private final String name;
+        private final String table;
+
+        public Builder(String name, String table) {
+            this.name = name;
+            this.table = table;
+        }
+
+        public DropConstraintOperation build() {
+            return new DropConstraintOperation(name, table);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/DropFieldOperation.java

@@ -0,0 +1,27 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class DropFieldOperation implements MigrationOperation {
+    private final String table;
+    private final String field;
+
+    public static class Builder implements MigrationOperation.Builder<DropFieldOperation> {
+        private final String table;
+        private final String field;
+
+        public Builder(String table, String field) {
+            this.table = table;
+            this.field = field;
+        }
+
+        public DropFieldOperation build() {
+            return new DropFieldOperation(table, field);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/DropTableOperation.java

@@ -0,0 +1,24 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class DropTableOperation implements MigrationOperation {
+    private final String table;
+
+    public static class Builder implements MigrationOperation.Builder<DropTableOperation> {
+        private final String table;
+
+        public Builder(String table) {
+            this.table = table;
+        }
+
+        public DropTableOperation build() {
+            return new DropTableOperation(table);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/MigrationOperation.java

@@ -0,0 +1,7 @@
+package jef.model.migration.operation;
+
+public interface MigrationOperation {
+    public interface Builder<T extends MigrationOperation> {
+        T build();
+    }
+}

src/main/java/jef/model/migration/operation/RenameFieldOperation.java

@@ -0,0 +1,30 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class RenameFieldOperation implements MigrationOperation {
+    private final String table;
+    private final String oldName;
+    private final String newName;
+
+    public static class Builder implements MigrationOperation.Builder<RenameFieldOperation> {
+        private final String table;
+        private final String oldName;
+        private final String newName;
+
+        public Builder(String table, String oldName, String newName) {
+            this.table = table;
+            this.oldName = oldName;
+            this.newName = newName;
+        }
+
+        public RenameFieldOperation build() {
+            return new RenameFieldOperation(table, oldName, newName);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/RenameTableOperation.java

@@ -0,0 +1,27 @@
+package jef.model.migration.operation;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class RenameTableOperation implements MigrationOperation {
+    private final String oldName;
+    private final String newName;
+
+    public static class Builder implements MigrationOperation.Builder<RenameTableOperation> {
+        private final String oldName;
+        private final String newName;
+
+        public Builder(String oldName, String newName) {
+            this.oldName = oldName;
+            this.newName = newName;
+        }
+
+        public RenameTableOperation build() {
+            return new RenameTableOperation(oldName, newName);
+        }
+    }
+}

src/main/java/jef/model/migration/operation/UpdateFieldOperation.java

@@ -0,0 +1,32 @@
+package jef.model.migration.operation;
+
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+public class UpdateFieldOperation extends AddFieldOperation {
+    private final String newName;
+
+    public UpdateFieldOperation(String table, String field, String newName, String sqlType, boolean notNull) {
+        super(table, field, sqlType, notNull);
+        this.newName = newName;
+    }
+
+    public static class Builder extends AddFieldOperation.Builder {
+        private String newName;
+
+        public Builder(String table, String field) {
+            super(table, field);
+        }
+
+        public Builder newName(String newName) {
+            this.newName = newName;
+            return this;
+        }
+
+        public UpdateFieldOperation build() {
+            return new UpdateFieldOperation(table, field, newName, sqlType, notNull);
+        }
+    }
+}

src/main/java/jef/util/Check.java

@@ -0,0 +1,10 @@
+package jef.util;
+
+public abstract class Check {
+    public static <T> T notNull(T t, String name) {
+        if (t == null) {
+            throw new IllegalArgumentException(name + " must be not null");
+        }
+        return t;
+    }
+}

src/main/java/jef/util/Util.java

@@ -0,0 +1,18 @@
+package jef.util;
+
+import java.util.Optional;
+
+public abstract class Util {
+    public static <T> Optional<T> tryGet(ThrowableSupplier<T> s) {
+        try {
+            return Optional.ofNullable(s.get());
+        } catch (Throwable t) {
+            return Optional.empty();
+        }
+    }
+
+    @FunctionalInterface
+    public interface ThrowableSupplier<T> {
+        T get() throws Throwable;
+    }
+}

src/test/java/jef/model/DbContextSimpleTest.java

@@ -16,7 +16,7 @@ class DbContextSimpleTest {
     public void test() {
         var mb = ModelBuilder.from(Ctx.class);
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertEquals(5, mb.getEntity(TestClass.class).getFields().size());
         assertEquals(1, mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).count());

src/test/java/jef/model/EntityInitializerMultiple1To1RelationTest.java

@@ -16,8 +16,8 @@ class EntityInitializerMultiple1To1RelationTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(2, mb.getEntities().size());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass2.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));

src/test/java/jef/model/ForeignKeyInitializerNToNRelationTest.java

@@ -18,9 +18,9 @@ class ForeignKeyInitializerNToNRelationTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(3, mb.getEntities().size());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
-        assertEquals(Mapping.class.getSimpleName(), mb.getEntity(Mapping.class).getName());
+        assertEquals("rels", mb.getEntity(Mapping.class).getName());
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(Mapping.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(Mapping.class)));

src/test/java/jef/model/ForeignKeyInitializerNestedList2LayerTest.java

@@ -18,9 +18,9 @@ class ForeignKeyInitializerNestedList2LayerTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(3, mb.getEntities().size());
-        assertEquals(TestClass3.class.getSimpleName(), mb.getEntity(TestClass3.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass3.class).getName());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("nested2", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("nested", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass3.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass3.class)));
         assertTrue(mb.getEntity(TestClass2.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));

src/test/java/jef/model/ForeignKeyInitializerNestedListSimpleTest.java

@@ -18,8 +18,8 @@ class ForeignKeyInitializerNestedListSimpleTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(2, mb.getEntities().size());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("nested", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass2.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));

src/test/java/jef/model/ForeignKeyInitializerNestedObject2LayerTest.java

@@ -16,9 +16,9 @@ class ForeignKeyInitializerNestedObject2LayerTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(3, mb.getEntities().size());
-        assertEquals(TestClass3.class.getSimpleName(), mb.getEntity(TestClass3.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass3.class).getName());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("nested2", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("nested", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass3.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass3.class)));
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
@@ -57,14 +57,14 @@ class ForeignKeyInitializerNestedObject2LayerTest {
         assertEquals(mb.getEntity(TestClass3.class), mb.getEntity(TestClass3.class).getForeignKeys().get(0).getEntity());
         assertEquals(mb.getEntity(TestClass2.class), mb.getEntity(TestClass3.class).getForeignKeys().get(0).getReferencedEntity());
         assertEquals(mb.getEntity(TestClass3.class).getFields().stream().filter(e -> e.getName().equals("nested2I")).toList(),
-                mb.getEntity(TestClass3.class).getForeignKeys().get(0).getFields());
+                     mb.getEntity(TestClass3.class).getForeignKeys().get(0).getFields());
         assertEquals(mb.getEntity(TestClass2.class).getPrimaryKey().getFields(), mb.getEntity(TestClass3.class).getForeignKeys().get(0).getReferencedFields());
 
         //refs TestClass2, TestClass
         assertEquals(mb.getEntity(TestClass2.class), mb.getEntity(TestClass2.class).getForeignKeys().get(0).getEntity());
         assertEquals(mb.getEntity(TestClass.class), mb.getEntity(TestClass2.class).getForeignKeys().get(0).getReferencedEntity());
         assertEquals(mb.getEntity(TestClass2.class).getFields().stream().filter(e -> e.getName().equals("nestedI")).toList(),
-                mb.getEntity(TestClass2.class).getForeignKeys().get(0).getFields());
+                     mb.getEntity(TestClass2.class).getForeignKeys().get(0).getFields());
         assertEquals(mb.getEntity(TestClass.class).getPrimaryKey().getFields(), mb.getEntity(TestClass2.class).getForeignKeys().get(0).getReferencedFields());
         // /keys ------------------------
     }

src/test/java/jef/model/ForeignKeyInitializerNestedObjectSimpleTest.java

@@ -16,8 +16,8 @@ class ForeignKeyInitializerNestedObjectSimpleTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(2, mb.getEntities().size());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass2.class).getName());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("nested", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass2.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));

src/test/java/jef/model/ForeignKeyInitializerRecursive1To1RelationTest.java

@@ -16,7 +16,7 @@ class ForeignKeyInitializerRecursive1To1RelationTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
 

src/test/java/jef/model/ForeignKeyInitializerRecursive1ToNRelationTest.java

@@ -18,7 +18,7 @@ class ForeignKeyInitializerRecursive1ToNRelationTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
 

src/test/java/jef/model/ForeignKeyInitializerRecursiveWithParent1ToNRelationTest.java

@@ -18,7 +18,7 @@ class ForeignKeyInitializerRecursiveWithParent1ToNRelationTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
 

src/test/java/jef/model/ModelBuilderCloneTest.java

@@ -0,0 +1,258 @@
+package jef.model;
+
+import jef.DbSet;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.annotations.Index;
+import jef.model.annotations.Key;
+import jef.model.annotations.Unique;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Objects;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class ModelBuilderCloneTest {
+    @Test
+    public void testClone() {
+        var mb = ModelBuilder.from(Ctx.class);
+        var copy = mb.clone();
+
+        debugHelper(mb, copy);
+
+        //true check
+        assertEquals(mb, copy);
+
+        //proper clone reference checks
+        for (int i = 0; i < mb.getEntities().size(); i++) {
+            assertTrue(mb.getEntities().get(i) != copy.getEntities().get(i));
+            for (int j = 0; j < mb.getEntities().get(0).getFields().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getFields().get(j) != copy.getEntities().get(i).getFields().get(j));
+                assertTrue(mb.getEntities().get(i).getFields().get(j).getEntity() != copy.getEntities().get(i).getFields().get(j).getEntity());
+            }
+
+            assertTrue(mb.getEntities().get(i).getPrimaryKey() != copy.getEntities().get(i).getPrimaryKey());
+            assertTrue(mb.getEntities().get(i).getPrimaryKey().getEntity() != copy.getEntities().get(i).getPrimaryKey().getEntity());
+
+            for (int j = 0; j < mb.getEntities().get(i).getPrimaryKey().getFields().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getPrimaryKey().getFields().get(j) != copy.getEntities().get(i).getPrimaryKey().getFields().get(j));
+                assertTrue(mb.getEntities().get(i).getPrimaryKey().getFields().get(j).getEntity() != copy.getEntities().get(i).getPrimaryKey().getFields().get(j).getEntity());
+            }
+
+            for (int j = 0; j < mb.getEntities().get(i).getForeignKeys().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getForeignKeys().get(j) != copy.getEntities().get(i).getForeignKeys().get(j));
+                assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getEntity() != copy.getEntities().get(i).getForeignKeys().get(j).getEntity());
+                assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getReferencedEntity() != copy.getEntities().get(i).getForeignKeys().get(j).getReferencedEntity());
+
+                for (int k = 0; k < mb.getEntities().get(i).getForeignKeys().get(j).getFields().size(); k++) {
+                    assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getFields().get(k) != copy.getEntities().get(i).getForeignKeys().get(j).getFields().get(k));
+                    assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getFields().get(k).getEntity() != copy.getEntities().get(i).getForeignKeys().get(j).getFields().get(k).getEntity());
+                }
+
+                for (int k = 0; k < mb.getEntities().get(i).getForeignKeys().get(j).getReferencedFields().size(); k++) {
+                    assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getReferencedFields().get(k) != copy.getEntities().get(i).getForeignKeys().get(j).getReferencedFields().get(k));
+                    assertTrue(mb.getEntities().get(i).getForeignKeys().get(j).getReferencedFields().get(k).getEntity() != copy.getEntities().get(i).getForeignKeys().get(j).getReferencedFields().get(k).getEntity());
+                }
+            }
+
+            for (int j = 0; j < mb.getEntities().get(i).getUniqueKeys().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getUniqueKeys().get(j) != copy.getEntities().get(i).getUniqueKeys().get(j));
+                assertTrue(mb.getEntities().get(i).getUniqueKeys().get(j).getEntity() != copy.getEntities().get(i).getUniqueKeys().get(j).getEntity());
+
+                for (int k = 0; k < mb.getEntities().get(i).getUniqueKeys().get(j).getFields().size(); k++) {
+                    assertTrue(mb.getEntities().get(i).getUniqueKeys().get(j).getFields().get(k) != copy.getEntities().get(i).getUniqueKeys().get(j).getFields().get(k));
+                    assertTrue(mb.getEntities().get(i).getUniqueKeys().get(j).getFields().get(k).getEntity() != copy.getEntities().get(i).getUniqueKeys().get(j).getFields().get(k).getEntity());
+                }
+            }
+
+            for (int j = 0; j < mb.getEntities().get(i).getKeys().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getKeys().get(j) != copy.getEntities().get(i).getKeys().get(j));
+                assertTrue(mb.getEntities().get(i).getKeys().get(j).getEntity() != copy.getEntities().get(i).getKeys().get(j).getEntity());
+
+                for (int k = 0; k < mb.getEntities().get(i).getKeys().get(j).getFields().size(); k++) {
+                    assertTrue(mb.getEntities().get(i).getKeys().get(j).getFields().get(k) != copy.getEntities().get(i).getKeys().get(j).getFields().get(k));
+                    assertTrue(mb.getEntities().get(i).getKeys().get(j).getFields().get(k).getEntity() != copy.getEntities().get(i).getKeys().get(j).getFields().get(k).getEntity());
+                }
+            }
+
+            for (int j = 0; j < mb.getEntities().get(i).getIndexes().size(); j++) {
+                assertTrue(mb.getEntities().get(i).getIndexes().get(j) != copy.getEntities().get(i).getIndexes().get(j));
+                assertTrue(mb.getEntities().get(i).getIndexes().get(j).getEntity() != copy.getEntities().get(i).getIndexes().get(j).getEntity());
+
+                for (int k = 0; k < mb.getEntities().get(i).getIndexes().get(j).getFields().size(); k++) {
+                    assertTrue(mb.getEntities().get(i).getIndexes().get(j).getFields().get(k) != copy.getEntities().get(i).getIndexes().get(j).getFields().get(k));
+                    assertTrue(mb.getEntities().get(i).getIndexes().get(j).getFields().get(k).getEntity() != copy.getEntities().get(i).getIndexes().get(j).getFields().get(k).getEntity());
+                }
+            }
+        }
+    }
+
+    public static void debugHelper(ModelBuilder expected, ModelBuilder actual) {
+        //debug helpers
+        assertEquals(expected.getEntities().size(), actual.getEntities().size());
+        for (int i = 0; i < expected.getEntities().size(); i++) {
+            var o = expected.getEntities().get(i);
+            var c = actual.getEntities().get(i);
+            if (!o.getTypeName().equals(c.getTypeName())) {
+                System.out.println("typenames differ: entity " + o.getName());
+                System.out.println("ex: " + o.getTypeName());
+                System.out.println("ac: " + c.getTypeName());
+            }
+            if (!Objects.equals(o.getType(), c.getType())) {
+                System.out.println("types differ: entity " + o.getName());
+                System.out.println("ex: " + o.getType());
+                System.out.println("ac: " + c.getType());
+            }
+            if (!o.getName().equals(c.getName())) {
+                System.out.println("names differ: entity " + o.getName());
+                System.out.println("ex: " + o.getName());
+                System.out.println("ac: " + c.getName());
+            }
+            if (!Objects.equals(o.getPrimaryKey(), c.getPrimaryKey())) {
+                System.out.println("primary keys differ: entity " + o.getName());
+                System.out.println("ex: " + o.getPrimaryKey());
+                System.out.println("ac: " + c.getPrimaryKey());
+            }
+
+            assertEquals(o.getForeignKeys().size(), c.getForeignKeys().size());
+            for (int j = 0; j < o.getForeignKeys().size(); j++) {
+                var ok = o.getForeignKeys().get(j);
+                var ck = c.getForeignKeys().get(j);
+                if (!Objects.equals(ok, ck)) {
+                    System.out.println("foreign keys differ: entity " + o.getName());
+                    System.out.println("ex: " + ok);
+                    System.out.println("ac: " + ck);
+                }
+            }
+
+            assertEquals(o.getUniqueKeys().size(), c.getUniqueKeys().size());
+            for (int j = 0; j < o.getUniqueKeys().size(); j++) {
+                var ok = o.getUniqueKeys().get(j);
+                var ck = c.getUniqueKeys().get(j);
+                if (!Objects.equals(ok, ck)) {
+                    System.out.println("unique keys differ: entity " + o.getName());
+                    System.out.println("ex: " + ok);
+                    System.out.println("ac: " + ck);
+                }
+            }
+
+            assertEquals(o.getKeys().size(), c.getKeys().size());
+            for (int j = 0; j < o.getKeys().size(); j++) {
+                var ok = o.getKeys().get(j);
+                var ck = c.getKeys().get(j);
+                if (!Objects.equals(ok, ck)) {
+                    System.out.println("keys differ: entity " + o.getName());
+                    System.out.println("ex: " + ok);
+                    System.out.println("ac: " + ck);
+                }
+            }
+
+            assertEquals(o.getIndexes().size(), c.getIndexes().size());
+            for (int j = 0; j < o.getIndexes().size(); j++) {
+                var ok = o.getIndexes().get(j);
+                var ck = c.getIndexes().get(j);
+                if (!Objects.equals(ok, ck)) {
+                    System.out.println("indexes differ: entity " + o.getName());
+                    System.out.println("ex: " + ok);
+                    System.out.println("ac: " + ck);
+                }
+            }
+
+            assertEquals(o.getFields().size(), c.getFields().size());
+            for (int j = 0; j < o.getIndexes().size(); j++) {
+                var of = o.getFields().get(j);
+                var cf = c.getFields().get(j);
+
+                if (of.isModelField() != cf.isModelField()) {
+                    System.out.println("is model fields differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.isModelField());
+                    System.out.println("ac: " + cf.isModelField());
+                }
+                if (of.isDatabaseField() != cf.isDatabaseField()) {
+                    System.out.println("is database fields differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.isDatabaseField());
+                    System.out.println("ac: " + cf.isDatabaseField());
+                }
+                if (of.isNotNull() != cf.isNotNull()) {
+                    System.out.println("is notnull differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.isNotNull());
+                    System.out.println("ac: " + cf.isNotNull());
+                }
+                if (!of.getEntity().getName().equals(cf.getEntity().getName())) {
+                    System.out.println("entities differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.getEntity().getName());
+                    System.out.println("ac: " + cf.getEntity().getName());
+                }
+                if (!of.getTypeName().equals(cf.getTypeName())) {
+                    System.out.println("typenames differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.getTypeName());
+                    System.out.println("ac: " + cf.getTypeName());
+                }
+                if (!Objects.equals(of.getType(), cf.getType())) {
+                    System.out.println("types differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.getType());
+                    System.out.println("ac: " + cf.getType());
+                }
+                if (!Objects.equals(of.getField() == null ? null : of.getField().getName(), cf.getField() == null ? null : cf.getField().getName())) {
+                    System.out.println("fields differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.getField());
+                    System.out.println("ac: " + cf.getField());
+                }
+                if (!Objects.equals(of.getForeignKeyModelLink() == null ? null : of.getForeignKeyModelLink().getName(),
+                                    cf.getForeignKeyModelLink() == null ? null : cf.getForeignKeyModelLink().getName())) {
+                    System.out.println("fk model links differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + (of.getForeignKeyModelLink() == null ? null : of.getForeignKeyModelLink().getName()));
+                    System.out.println("ac: " + (cf.getForeignKeyModelLink() == null ? null : cf.getForeignKeyModelLink().getName()));
+                }
+                if (!of.getName().equals(cf.getName())) {
+                    System.out.println("names differ: entity " + o.getName() + ", field " + of.getName());
+                    System.out.println("ex: " + of.getName());
+                    System.out.println("ac: " + cf.getName());
+                }
+
+//                if (!Objects.equals(of, cf)) {
+//                    System.out.println("fields differ: entity " + o.getName() + ", field " + of.getName());
+//                    System.out.println("ex: " + of);
+//                    System.out.println("ac: " + cf);
+//                }
+            }
+        }
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects2;
+        @Clazz(clazz = TestClass.class)
+        private DbSet<TestClass> objects1;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        @Key
+        public double d;
+        @Index
+        public float f;
+        @Unique
+        public long l;
+        private TestClass previous;
+        private TestClass next;
+        @Clazz(clazz = TestClass.class)
+        private List<TestClass> children;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public TestClass o;
+        public TestClass o2;
+    }
+}

src/test/java/jef/model/ModelBuilderSimpleTest.java

@@ -0,0 +1,43 @@
+package jef.model;
+
+import jef.DbSet;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.annotations.Index;
+import jef.model.annotations.Key;
+import jef.model.annotations.Unique;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ModelBuilderSimpleTest {
+    @Test
+    public void testClone() {
+        var mb = ModelBuilder.from(Ctx.class);
+
+        assertEquals(1, mb.getEntities().size());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
+        assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass.class)
+        private DbSet<TestClass> objects1;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+
+}

src/test/java/jef/model/annotations/processors/ForeignKeyProcessorExposeTest.java

@@ -19,8 +19,8 @@ class ForeignKeyProcessorExposeTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(2, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass2.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));

src/test/java/jef/model/annotations/processors/ForeignKeyProcessorSelfReferenceTest.java

@@ -19,7 +19,7 @@ class ForeignKeyProcessorSelfReferenceTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
 

src/test/java/jef/model/annotations/processors/ForeignKeyProcessorSimpleTest.java

@@ -19,8 +19,8 @@ class ForeignKeyProcessorSimpleTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(2, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
-        assertEquals(TestClass2.class.getSimpleName(), mb.getEntity(TestClass2.class).getName());
+        assertEquals("objects2", mb.getEntity(TestClass2.class).getName());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));
         assertTrue(mb.getEntity(TestClass2.class).getFields().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass2.class)));
         assertTrue(mb.getEntity(TestClass.class).getForeignKeys().stream().allMatch(e -> e.getEntity() == mb.getEntity(TestClass.class)));

src/test/java/jef/model/annotations/processors/IndexProcessorClassTest.java

@@ -19,7 +19,7 @@ class IndexProcessorClassTest {
         var mb = ModelBuilder.from(CtxIndexOnClass.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isIndex());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isIndex());

src/test/java/jef/model/annotations/processors/IndexProcessorFieldTest.java

@@ -19,7 +19,7 @@ class IndexProcessorFieldTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isIndex());
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isIndex());

src/test/java/jef/model/annotations/processors/KeyProcessorClassTest.java

@@ -19,7 +19,7 @@ class KeyProcessorClassTest {
         var mb = ModelBuilder.from(CtxKeyOnClass.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isKey());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isKey());

src/test/java/jef/model/annotations/processors/KeyProcessorFieldTest.java

@@ -19,7 +19,7 @@ class KeyProcessorFieldTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isKey());
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isKey());

src/test/java/jef/model/annotations/processors/NotNullProcessorTest.java

@@ -19,7 +19,7 @@ class NotNullProcessorTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isNotNull());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isNotNull());

src/test/java/jef/model/annotations/processors/UniqueProcessorClassTest.java

@@ -19,7 +19,7 @@ class UniqueProcessorClassTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isUnique());
         assertTrue(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isUnique());

src/test/java/jef/model/annotations/processors/UniqueProcessorFieldTest.java

@@ -19,7 +19,7 @@ class UniqueProcessorFieldTest {
         var mb = ModelBuilder.from(Ctx.class);
 
         assertEquals(1, mb.getEntities().size());
-        assertEquals(TestClass.class.getSimpleName(), mb.getEntity(TestClass.class).getName());
+        assertEquals("objects1", mb.getEntity(TestClass.class).getName());
 
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("i")).findFirst().get().isUnique());
         assertFalse(mb.getEntity(TestClass.class).getFields().stream().filter(e -> e.getName().equals("d")).findFirst().get().isUnique());

src/test/java/jef/model/migration/creator/MigrationCreatorAddEntityTest.java

@@ -0,0 +1,111 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.constraints.PrimaryKeyConstraint;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddTableOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropTableOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddEntityTest extends MigrationCreatorTestBase {
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getOrCreateEntity("AddedEntity");
+        ent.getOrCreateField("id", int.class.getName());
+        ent.getOrCreateField("addedField", int.class.getName());
+        ent.setPrimaryKey(new PrimaryKeyConstraint(ent, List.of(ent.getField("id"))));
+        ent.addForeignKey(new ForeignKeyConstraint(ent, List.of(ent.getField("addedField")), ent, List.of(ent.getField("id")), ForeignKeyConstraint.Action.CASCADE, ForeignKeyConstraint.Action.CASCADE));
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(3, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddTableOperation o
+                             && o.getTable().equals("AddedEntity")
+                             && o.getFields().size() == 2
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("id")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("addedField")).count() == 1)
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("AddedEntity")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("id"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("AddedEntity")
+                             && o.getReferencedTable().equals("AddedEntity")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("addedField")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("id"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(3, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("AddedEntity")
+                             && o.getName().equals("FK_AddedEntity_AddedEntity_addedField"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("AddedEntity")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropTableOperation o
+                             && o.getTable().equals("AddedEntity"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorAddFieldTest.java

@@ -0,0 +1,95 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.migration.operation.AddFieldOperation;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropFieldOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddFieldTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass2.class);
+        ent.getOrCreateField("addedField", int.class.getName());
+        ent.addForeignKey(new ForeignKeyConstraint(ent, List.of(ent.getField("addedField")), ent, List.of(ent.getField("i")), ForeignKeyConstraint.Action.CASCADE, ForeignKeyConstraint.Action.CASCADE));
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(2, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddFieldOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getField().equals("addedField"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getReferencedTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("addedField")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(2, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getName().equals("FK_objects1_objects1_addedField"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropFieldOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getField().equals("addedField"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorAddForeignKeyTest.java

@@ -0,0 +1,83 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.constraints.ForeignKeyConstraint;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddForeignKeyTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.addForeignKey(new ForeignKeyConstraint(ent, List.of(ent.getField("i2")), ent, List.of(ent.getField("i")), ForeignKeyConstraint.Action.CASCADE, ForeignKeyConstraint.Action.CASCADE));
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getReferencedTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i2")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("FK_nested_nested_i2"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public int i2 = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorAddIndexTest.java

@@ -0,0 +1,78 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.AddIndexOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddIndexTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.getField("d").setIndex(true);
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddIndexOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("d"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("I_nested_d"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorAddKeyTest.java

@@ -0,0 +1,78 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.AddKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddKeyTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.getField("d").setKey(true);
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("d"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("K_nested_d"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorAddUniqueTest.java

@@ -0,0 +1,78 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.AddUniqueKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorAddUniqueTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.getField("d").setUnique(true);
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddUniqueKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("d"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("U_nested_d"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorEmptyTest.java

@@ -0,0 +1,61 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.annotations.Index;
+import jef.model.annotations.Key;
+import jef.model.annotations.Unique;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorEmptyTest  extends MigrationCreatorTestBase{
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "EmptyMigration", "test",new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            assertEquals(0, res.getStepsUp().size());
+            assertEquals(0, res.getStepsDown().size());
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        @Index
+        public double d;
+        @Unique
+        public float f;
+        @Key
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorInitialMigrationTest.java

@@ -0,0 +1,130 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddTableOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.DropTableOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorInitialMigrationTest extends MigrationCreatorTestBase {
+    @Test
+    public void test() {
+        var from = new ModelBuilder(List.of());
+        var to = ModelBuilder.from(Ctx.class);
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "InitialMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(5, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddTableOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).build().getField().equals("i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddTableOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 6
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("d")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("f")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("i")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("l")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("o")).count() == 1
+                             && o.getFields().stream().filter(f -> f.build().getField().equals("nestedI")).count() == 1)
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getReferencedTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("nestedI")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(5, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("FK_nested_objects1_nestedI"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("objects1")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropTableOperation o
+                             && o.getTable().equals("nested"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropTableOperation o
+                             && o.getTable().equals("objects1"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorRenameEntityTest.java

@@ -0,0 +1,129 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.RenameTableOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorRenameEntityTest extends MigrationCreatorTestBase {
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.setName("d2");
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(5, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("FK_nested_objects1_nestedI"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof RenameTableOperation o
+                             && o.getOldName().equals("nested")
+                             && o.getNewName().equals("d2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("d2")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("d2")
+                             && o.getReferencedTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("nestedI")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(5, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("d2")
+                             && o.getName().equals("FK_d2_objects1_nestedI"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("d2")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof RenameTableOperation o
+                             && o.getOldName().equals("d2")
+                             && o.getNewName().equals("nested"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getReferencedTable().equals("objects1")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("nestedI")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorRenameFieldConstraintsTest.java

@@ -0,0 +1,210 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.ForeignKey;
+import jef.model.annotations.Id;
+import jef.model.annotations.Index;
+import jef.model.annotations.Key;
+import jef.model.annotations.Unique;
+import jef.model.migration.operation.AddForeignKeyOperation;
+import jef.model.migration.operation.AddIndexOperation;
+import jef.model.migration.operation.AddKeyOperation;
+import jef.model.migration.operation.AddPrimaryKeyOperation;
+import jef.model.migration.operation.AddUniqueKeyOperation;
+import jef.model.migration.operation.DropConstraintOperation;
+import jef.model.migration.operation.RenameFieldOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorRenameFieldConstraintsTest extends MigrationCreatorTestBase {
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        to.getEntity(TestClass.class).getField("i").setName("i2");
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(11, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("FK_nested_nested_iFk"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("U_nested_i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("K_nested_i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("I_nested_i"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof RenameFieldOperation o
+                             && o.getTable().equals("nested")
+                             && o.getOldName().equals("i")
+                             && o.getNewName().equals("i2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getReferencedTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("iFk")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddUniqueKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i2"))
+                .count());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof AddIndexOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i2"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(11, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("FK_nested_nested_iFk"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("PRIMARY"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("U_nested_i2"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("K_nested_i2"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof DropConstraintOperation o
+                             && o.getTable().equals("nested")
+                             && o.getName().equals("I_nested_i2"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof RenameFieldOperation o
+                             && o.getTable().equals("nested")
+                             && o.getOldName().equals("i2")
+                             && o.getNewName().equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddPrimaryKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddForeignKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getReferencedTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("iFk")
+                             && o.getReferencedFields().size() == 1
+                             && o.getReferencedFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddUniqueKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddKeyOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof AddIndexOperation o
+                             && o.getTable().equals("nested")
+                             && o.getFields().size() == 1
+                             && o.getFields().get(0).equals("i"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+
+
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        @Index
+        @Unique
+        @Key
+        public int i = 1;
+        @ForeignKey(entity = TestClass.class, getterOrField = "i")
+        public int iFk = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorRenameFieldTest.java

@@ -0,0 +1,78 @@
+package jef.model.migration.creator;
+
+import jef.DbSet;
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.annotations.Clazz;
+import jef.model.annotations.Id;
+import jef.model.migration.operation.RenameFieldOperation;
+import jef.serializable.SerializableObject;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorRenameFieldTest extends MigrationCreatorTestBase {
+    @Test
+    public void test() {
+        var from = ModelBuilder.from(Ctx.class);
+        var to = ModelBuilder.from(Ctx.class);
+        var ent = to.getEntity(TestClass.class);
+        ent.getField("d").setName("d2");
+        var mc = new MigrationCreator();
+        var res = mc.createMigration(from, to, "SomeMigration", "test", new ModelBuilderGenerator(from, "Current", "test").generate().getJava());
+        try {
+            validateUp(res);
+            validateDown(res);
+        } catch (Throwable t) {
+            System.out.println(res.getMigration());
+            throw t;
+        }
+        validateMigration(res, from, to);
+    }
+
+    private void validateUp(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsUp().size());
+        assertEquals(1, res.getStepsUp().stream()
+                .filter(e -> e instanceof RenameFieldOperation o
+                             && o.getTable().equals("nested")
+                             && o.getOldName().equals("d")
+                             && o.getNewName().equals("d2"))
+                .count());
+    }
+
+    private void validateDown(MigrationCreator.Result res) {
+        assertEquals(1, res.getStepsDown().size());
+        assertEquals(1, res.getStepsDown().stream()
+                .filter(e -> e instanceof RenameFieldOperation o
+                             && o.getTable().equals("nested")
+                             && o.getOldName().equals("d2")
+                             && o.getNewName().equals("d"))
+                .count());
+    }
+
+    public static class Ctx extends DbContext {
+        @Clazz(clazz = TestClass2.class)
+        private DbSet<TestClass2> objects1;
+    }
+
+    @Getter
+    public static class TestClass2 extends SerializableObject {
+        @Id
+        public int i = 1;
+        @Clazz(clazz = TestClass.class)
+        public List<TestClass> nested;
+    }
+
+    @Getter
+    public static class TestClass extends SerializableObject {
+        @Id
+        public int i = 1;
+        public Object o = new Object();
+        public double d;
+        public float f;
+        public long l;
+    }
+}

src/test/java/jef/model/migration/creator/MigrationCreatorTestBase.java

@@ -0,0 +1,142 @@
+package jef.model.migration.creator;
+
+import jef.model.DbContext;
+import jef.model.ModelBuilder;
+import jef.model.ModelBuilderCloneTest;
+
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.StandardOpenOption;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class MigrationCreatorTestBase {
+    private static final File JAVA_FILES_DIR = new File("target/jef-tests/sources");
+    private static final File CLASS_FILES_DIR = new File("target/jef-tests/classes");
+
+    public void validateMigration(MigrationCreator.Result result, ModelBuilder from, ModelBuilder to) {
+        validateMigrationJava(result.getMigration());
+        validatePreMigrationSnapshotJava(result.getMigrationSnapshot(), from);
+        validatePostMigrationSnapshotJava(result.getCurrentSnapshot(), to);
+    }
+
+    public void validateMigrationJava(String migrationJava) {
+        try {
+            var packageName = findPackageName(migrationJava);
+            var className = findClassName(migrationJava);
+            compile(packageName, className, migrationJava);
+            var clazz = loadClass(packageName, className);
+            //for migration just test if it's compiling
+        } catch (AssertionError | RuntimeException e) {
+            throw e;
+        } catch (Throwable t) {
+            throw new RuntimeException("Failed to load generated class", t);
+        }
+    }
+
+    public void validatePreMigrationSnapshotJava(String snapshotJava, ModelBuilder from) {
+        try {
+            var packageName = findPackageName(snapshotJava);
+            var className = findClassName(snapshotJava);
+            compile(packageName, className, snapshotJava);
+            var clazz = (Class<? extends DbContext>) loadClass(packageName, className);
+            var mb = ModelBuilder.from(clazz);
+            ModelBuilderCloneTest.debugHelper(from, mb);
+            assertEquals(from, mb);
+        } catch (AssertionError | RuntimeException e) {
+            throw e;
+        } catch (Throwable t) {
+            throw new RuntimeException("Failed to load generated class", t);
+        }
+    }
+
+    public void validatePostMigrationSnapshotJava(String snapshotJava, ModelBuilder to) {
+        try {
+            var packageName = findPackageName(snapshotJava);
+            var className = findClassName(snapshotJava);
+            compile(packageName, className, snapshotJava);
+            var clazz = (Class<? extends DbContext>) loadClass(packageName, className);
+            var mb = ModelBuilder.from(clazz);
+            assertEquals(to, mb);
+        } catch (AssertionError | RuntimeException e) {
+            throw e;
+        } catch (Throwable t) {
+            throw new RuntimeException("Failed to load generated class", t);
+        }
+    }
+
+    private File compile(String packageName, String className, String java) {
+        try {//src
+            File srcdir = new File(getSourcesFilesDir(), packageName.replace(".", File.separator));
+            srcdir.mkdirs();
+            File srcf = new File(srcdir, className + ".java");
+            Files.writeString(srcf.toPath(), java, StandardCharsets.UTF_8,
+                              StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE);
+
+            //dest
+            File destdir = getClassFilesDir();
+            var process = new ProcessBuilder()
+                    .command("javac", //TODO use javac for current jdk
+                             "-cp", "target/classes" + File.pathSeparator + "target/test-classes",
+                             "-encoding", "UTF8",
+                             "-g", //debug symbols
+                             "-d", destdir.getPath(), //target
+                             srcf.getPath()
+                    )
+                    .inheritIO()
+                    .start();
+            process.waitFor(10, TimeUnit.SECONDS);
+            var exitCode = process.exitValue();
+            assertEquals(0, exitCode, "Compilation failed");
+
+            return new File(new File(destdir, packageName.replace(".", File.separator)), srcf.getName().replace(".java", ".class"));
+        } catch (AssertionError | RuntimeException e) {
+            throw e;
+        } catch (Throwable t) {
+            throw new RuntimeException("Error while compiling generated class", t);
+        }
+    }
+
+    private Class<?> loadClass(String packageName, String className) {
+        try {
+            var cl = new URLClassLoader(new URL[]{getClassFilesDir().toURL()});
+            return cl.loadClass(packageName + "." + className);
+        } catch (AssertionError | RuntimeException e) {
+            throw e;
+        } catch (Throwable t) {
+            throw new RuntimeException("Failed to load generated class", t);
+        }
+    }
+
+    private String findPackageName(String java) {
+        Pattern p = Pattern.compile("package ([^;]+);");
+        Matcher m = p.matcher(java);
+        m.find();
+        return m.group(1);
+    }
+
+    private String findClassName(String java) {
+        Pattern p = Pattern.compile("public class ([^ ]+)");
+        Matcher m = p.matcher(java);
+        m.find();
+        return m.group(1);
+    }
+
+    private File getSourcesFilesDir() {
+        File srcdir = new File(JAVA_FILES_DIR, getClass().getSimpleName());
+        srcdir.mkdirs();
+        return srcdir;
+    }
+
+    private File getClassFilesDir() {
+        File destdir = new File(CLASS_FILES_DIR, getClass().getSimpleName());
+        destdir.mkdirs();
+        return destdir;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddEntityTest.java

@@ -0,0 +1,45 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddEntityTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(0, cd.getFrom().getEntities().size());
+
+        assertEquals(2, cd.getTo().getEntities().size());
+        assertEquals(1, cd.getTo().getEntities().get(0).getFields().size());
+        assertEquals(1, cd.getTo().getEntities().get(1).getFields().size());
+        assertEquals("i2", cd.getTo().getEntities().get(0).getFields().get(0).getName());
+        assertEquals("i3", cd.getTo().getEntities().get(1).getFields().get(0).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass2");
+        mb.getOrCreateEntity("TestClass2").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass3");
+        mb.getOrCreateEntity("TestClass3").getOrCreateField("i3", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddFieldTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddFieldTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(0, cd.getFrom().getEntities().get(0).getFields().size());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(2, cd.getTo().getEntities().get(0).getFields().size());
+        assertEquals("i2", cd.getTo().getEntities().get(0).getFields().get(0).getName());
+        assertEquals("i3", cd.getTo().getEntities().get(0).getFields().get(1).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i3", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddForeignKeyTest.java

@@ -0,0 +1,48 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import jef.model.constraints.ForeignKeyConstraint;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddForeignKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(0, cd.getFrom().getEntities().get(0).getForeignKeys().size());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(1, cd.getTo().getEntities().get(0).getForeignKeys().size());
+        assertEquals("FK_TestClass_TestClass_i2", cd.getTo().getEntities().get(0).getForeignKeys().get(0).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        var ent = mb.getOrCreateEntity("TestClass");
+        ent.getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        ent.getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        ent.addForeignKey(new ForeignKeyConstraint(ent, List.of(ent.getField("i2")),
+                                                   ent, List.of(ent.getField("i")),
+                                                   ForeignKeyConstraint.Action.CASCADE, ForeignKeyConstraint.Action.CASCADE));
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddIndexTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddIndexTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(0, cd.getFrom().getEntities().get(0).getIndexes().size());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(1, cd.getTo().getEntities().get(0).getIndexes().size());
+        assertEquals("I_TestClass_i", cd.getTo().getEntities().get(0).getIndexes().get(0).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setIndex(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddKeyTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(0, cd.getFrom().getEntities().get(0).getKeys().size());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(1, cd.getTo().getEntities().get(0).getKeys().size());
+        assertEquals("K_TestClass_i", cd.getTo().getEntities().get(0).getKeys().get(0).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setKey(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddPrimaryKeyTest.java

@@ -0,0 +1,48 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import jef.model.constraints.PrimaryKeyConstraint;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class ModelChangeDetectorAddPrimaryKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertNull(cd.getFrom().getEntities().get(0).getPrimaryKey());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertNotNull(cd.getTo().getEntities().get(0).getPrimaryKey());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").setPrimaryKey(new PrimaryKeyConstraint(mb.getOrCreateEntity("TestClass"),
+                                                                                 List.of(mb.getOrCreateEntity("TestClass").getField("i"))));
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorAddUniqueTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorAddUniqueTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(0, cd.getFrom().getEntities().get(0).getUniqueKeys().size());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(1, cd.getTo().getEntities().get(0).getUniqueKeys().size());
+        assertEquals("U_TestClass_i", cd.getTo().getEntities().get(0).getUniqueKeys().get(0).getName());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setUnique(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropEntityTest.java

@@ -0,0 +1,45 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropEntityTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(2, cd.getFrom().getEntities().size());
+        assertEquals(1, cd.getFrom().getEntities().get(0).getFields().size());
+        assertEquals(1, cd.getFrom().getEntities().get(1).getFields().size());
+        assertEquals("i2", cd.getFrom().getEntities().get(0).getFields().get(0).getName());
+        assertEquals("i3", cd.getFrom().getEntities().get(1).getFields().get(0).getName());
+
+        assertEquals(0, cd.getTo().getEntities().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass2");
+        mb.getOrCreateEntity("TestClass2").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass3");
+        mb.getOrCreateEntity("TestClass3").getOrCreateField("i3", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropFieldTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropFieldTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(2, cd.getFrom().getEntities().get(0).getFields().size());
+        assertEquals("i2", cd.getFrom().getEntities().get(0).getFields().get(0).getName());
+        assertEquals("i3", cd.getFrom().getEntities().get(0).getFields().get(1).getName());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(0, cd.getTo().getEntities().get(0).getFields().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i3", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropForeignKeyTest.java

@@ -0,0 +1,48 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import jef.model.constraints.ForeignKeyConstraint;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropForeignKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(1, cd.getFrom().getEntities().get(0).getForeignKeys().size());
+        assertEquals("FK_TestClass_TestClass_i2", cd.getFrom().getEntities().get(0).getForeignKeys().get(0).getName());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(0, cd.getTo().getEntities().get(0).getForeignKeys().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        var ent = mb.getOrCreateEntity("TestClass");
+        ent.getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        ent.getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        ent.addForeignKey(new ForeignKeyConstraint(ent, List.of(ent.getField("i2")),
+                                                   ent, List.of(ent.getField("i")),
+                                                   ForeignKeyConstraint.Action.CASCADE, ForeignKeyConstraint.Action.CASCADE));
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropIndexTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropIndexTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(1, cd.getFrom().getEntities().get(0).getIndexes().size());
+        assertEquals("I_TestClass_i", cd.getFrom().getEntities().get(0).getIndexes().get(0).getName());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(0, cd.getTo().getEntities().get(0).getIndexes().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setIndex(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropKeyTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(1, cd.getFrom().getEntities().get(0).getKeys().size());
+        assertEquals("K_TestClass_i", cd.getFrom().getEntities().get(0).getKeys().get(0).getName());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(0, cd.getTo().getEntities().get(0).getKeys().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setKey(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropPrimaryKeyTest.java

@@ -0,0 +1,48 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import jef.model.constraints.PrimaryKeyConstraint;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class ModelChangeDetectorDropPrimaryKeyTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertNotNull(cd.getFrom().getEntities().get(0).getPrimaryKey());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertNull(cd.getTo().getEntities().get(0).getPrimaryKey());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").setPrimaryKey(new PrimaryKeyConstraint(mb.getOrCreateEntity("TestClass"),
+                                                                                 List.of(mb.getOrCreateEntity("TestClass").getField("i"))));
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorDropUniqueTest.java

@@ -0,0 +1,43 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ModelChangeDetectorDropUniqueTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+
+        assertEquals(1, cd.getFrom().getEntities().size());
+        assertEquals(1, cd.getFrom().getEntities().get(0).getUniqueKeys().size());
+        assertEquals("U_TestClass_i", cd.getFrom().getEntities().get(0).getUniqueKeys().get(0).getName());
+
+        assertEquals(1, cd.getTo().getEntities().size());
+        assertEquals(0, cd.getTo().getEntities().get(0).getUniqueKeys().size());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName()).setUnique(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+}

src/test/java/jef/model/migration/creator/ModelChangeDetectorNoChangeTest.java

@@ -0,0 +1,34 @@
+package jef.model.migration.creator;
+
+import jef.model.ModelBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ModelChangeDetectorNoChangeTest {
+    @Test
+    public void test() {
+        var from = createFrom();
+        var to = createTo();
+        var cd = new ModelChangeDetector(from, to).detect();
+        assertTrue(cd.getFrom().getEntities().isEmpty());
+        assertTrue(cd.getTo().getEntities().isEmpty());
+    }
+
+    private ModelBuilder createFrom() {
+        var mb = new ModelBuilder();
+        mb.getOrCreateEntity("TestClass");
+        mb.getOrCreateEntity("TestClass").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass2");
+        mb.getOrCreateEntity("TestClass2").getOrCreateField("i", int.class.getName())
+                .setNotNull(true);
+        mb.getOrCreateEntity("TestClass2").getOrCreateField("i2", int.class.getName())
+                .setNotNull(true);
+        return mb;
+    }
+
+    private ModelBuilder createTo() {
+        return createFrom();
+    }
+}